It's hard to say for sure. However, it seems more likely that their primary motivations were not ideological antisemitism. When Israel first discovered the program, it was not due to intelligence work. Instead, Israel became aware of the program when Egyptian newspapers touted successful missile tests in 1962. Israelis were now terrified, as the news filtered to the public. A few weeks later, with reports that German scientists had helped, the Israeli public became even more afraid. One headline, according to Ronen Bergman's Rise and Kill First, trumpeted that "Former German Nazis are now helping Nasser in his anti-Israeli genocide projects". The Mossad was caught completely unawares, and also humiliated. These were senior Nazi scientists, many of them formerly employed at Peenemunde, where they helped build the V-1 and V-2 rockets. The Israeli Defense Ministry's director-general said he felt helpless upon hearing the news, and Ben-Gurion described the nightmare keeping him up at night as being that he, as the first Israeli Prime Minister, had brought the surviving Jews of Europe to Israel only to have them undergo a second Holocaust. So, to put it lightly, the news was very important to Israel, which took investigating the scientists and program very seriously.

Israeli operatives began breaking into Egyptian consulates in Europe, stealing documents and recruiting spies that gave the Mossad access to Egyptian mail and thus intelligence documents. What they found was that the project began with Dr. Eugen Sanger and Wolfgang Pilz. Both had been at Peenemunde, and following the war, both had joined the Research Institute of Jet Propulsion Physics in Stuttgart following the war, which Sanger headed. Pilz, as well as two others (Dr. Paul Goercke and Dr. Heinz Krug), were heads of departments at the institute. Bergman says that the group felt "underemployed and underutilized" in postwar Germany, and thus approached the regime to offer the development of long-range missile capabilities, and to recruit and develop teams doing so. They relocated and recruited 35 German scientists and technicians, with huge salaries and good working conditions. Krug remained in Germany, setting up a company to be the European front of the operation. They began plans to manufacture up to 900 missiles, a huge sum and one that Israel uncovered. At this point, Israel began to take action. First, they captured Krug, but set up a disinformation operation where they made it seem like Krug had taken the money from Egypt and run away. This included a false paper trail that led through South America, to throw Egypt off the trail. They also made media "leaks" that he had fought with Egyptian leaders, and was abducted and killed by them. For months afterwards, Israel interrogated Krug, and through his evidently good memory, managed to construct a very good understanding of the missile project.

Krug even ended up offering to go back to Munich and be a Mossad agent. This may have been an attempt at escape, and obviously Mossad did not take this risk, but it is interesting to note. Krug was eventually deemed too dangerous to release, shot, and his body dumped in the sea.

It's unclear how all the scientists and operatives were motivated. After all, we're talking about more than 30 people, and people's motivations are rarely so clear as solely one thing. Some may have been motivated by salaries, but antisemitism helped make the case. Others may have had the opposite ratio.

The CIA notes that in 1953, Sanger had been approached by the Egyptians about helping with the missile program. At the time however, he turned them down; he apparently, they said, disliked the technical director of the project on a personal level and didn't want to work with him (Rolf Engel). The CIA report is redacted, but notes (as Bergman does) that the "foregoing information" (largely redacted portion is above):

...illustrates that there are a number of technically competent Germans who are frustrated by the lack of opportunity to develop missiles in Germany and are readily recruitable by other countries for that purpose.

You can read the report here (PDF warning).

At the same time, there are indications that plenty felt allegiance to Nazism or a "Fourth Reich", or at least were willing to say as much in some circumstances. Part of this is clear because of Israel's operations to infiltrate the group of scientists, actually. In May 1964, Israel considered recruiting Otto Skorzeny. Avraham Avituv, junction coordinator in Bonn, presented an idea to Rafi Eitan (an intelligence officer) to recruit him. He told Eitan that there is "just one small problem . . . the man's name is Otto Skorzeny, and he was a high-ranking Wehrmacht officer, Hitler's special-operations commander, and a favorite of the Fuhrer". Eitan sarcastically responded, "And you want to recruit this Otto? Wonderful." Ahituv, responding, threw in "There's one more small matter. He was a devoted Nazi and as member of the SS."

You can imagine how controversial this was. Israel had actually sought to have him captured or killed since 1960, but eventually decided he would be a valuable recruit if they could make him one, to get even bigger fish. Skorzeny insisted that he did not participate in the Holocaust, but it was absurd to claim as much. After a conversation with an Israeli intelligence operative (Ahituv, as it happens) under false pretenses, Skorzeny eventually got tired and asked Ahituv what he wanted. Ahituv explained that he was an Israeli operative, and Skorzeny expressed surprise that he hadn't been gotten to sooner. Skorzeny, in exchange for immunity and a "life without fear" as Bergman put it, agreed to cooperate fully with Israel. This was controversial, and I can get into the debates, but I'd like to move back to the main subject.

To infiltrate the German scientists' group, Skorzeny sent a message around the scientists in Egypt that he was "reviving a network of SS and Wehrmacht veterans 'to build a new Germany' . . . in other words, to establish a Fourth Reich." He hoped to convince them to share the information they were gathering and technology they were developing to create a "shadow military" for an eventual bid to take over Germany and make a new military force, which would in fact be a good way for Israel to gain an inside understanding of the Egyptian military project. He also created a plot to get into the good graces of Hermann Vallentin, a high-ranking official in the Egyptian project. Skorzeny, with Mossad footing the bill, hosted Vallentin in a luxurious hotel with dinners and the like, and shared his "plot" to create a "Fourth Reich". Then he asked Vallentin to meet with a British friend who worked for MI6 but was a "close friend". Vallentin was suspicious that the Israelis were involved, and asked Skorzeny as much, and Skorzeny dramatically fired back that he should apologize for maligning a superior officer so. Vallentin was, of course, correct; the "Brit" was actually an Australian-born Mossad agent. But the meeting went nowhere, so Skorzeny took another tack. In a future meeting, he informed Vallentin of a retroactive "promotion" within the Nazi ranks. Purely symbolic, Vallentin was still touched, and profusely thanked Skorzeny and even did the "Heil Hitler" salute. Eventually, Skorzeny was hosting other German scientists who hoped to revive Nazi Germany, with dinner parties and luxury galore, all ironically enough footed by the Israeli government. With the information, Israel mapped out the capabilities and personnel of the Egyptian missile project, and eventually took tactics to pressure or assassinate some of the scientists. Many were simply pressured out, in part because West Germany was convinced by Israel to assist. New groups of scientists sought for recruitment were instead offered jobs by Germany directly, or better conditions/salaries, and never went to Egypt. Others were pressured by West German officials, who traveled to Egypt to entice them back. Eventually, even Pilz would leave, becoming head of Bolkow's airplane components division, Bolkow being a big figure in Germany's aerospace industry. So assassination was not, in the end, what got rid of most of them. But many were still motivated at the very least by the promise of luxury and comradery with those they once worked with, and at least some still found the idea of a Fourth Reich attractive. To what extent this motivated them, versus the salary and other attractive factors, and how much this overlapped with a personal hatred for Jews, is hard to aggregate and know. Even so, at least some (and perhaps all) were likely quite antisemitic, even if that wasn't their primary motivation. It was with a mix of carrots (through West Germany for example) and sticks (threatening letters and a handful of assassinations or attempts) that the German scientists were eventually convinced to leave Egypt and its program.

It's worth noting one more thing: Israel authored a top-secret retrospective on the program in 1982. This was, in part, because Israel had (via this program) targeted civilians from countries it had relations with for the first time (i.e. West Germany). The analysis focused primarily on whether or not the Germans could have been motivated to drop their work using simply offers of jobs and money without killing Krug, or the letter bombs and threats. The report concluded that it could not have been done; the Mossad concluded that without the threat of violence, many of them would not have found money and jobs enough to give up the project. Which should, in and of itself, also indicate that there were deeper motivations at play than are sometimes assumed, even if they started with money as a primary motivation.