I think it's worth taking the remark in context. What is saying is, in many cases we are willing to say in retrospect that vast sacrifices of lives are worth it if there is a high payoff. He talks about World War I and World War II, both of which had very high death tolls, and notes that WWI is basically considered not worthwhile (its goals weren't great, its outcome wasn't great), but basically everybody thinks that the Allied involvement in World War II was worthwhile, despite the enormously high costs in getting it. He is then saying, that if the Soviet "radiant tomorrow" had worked out — and they had created a classless society of equity and freedom and all of the most utopic views of the Communists of the 1930s — that maybe people would see the costs of Stalin's reign to be ultimately worth it. (He doesn't put a timespan on this, as an aside. How many generations would need to pass is an interesting question to ask here. And frankly I think assuming any static opinion is a bad one. Americans, for example, have had mixed views about the necessity and "value" of slavery, for example, over the past 150 years — at times, some have felt it was a "necessary evil," while others have felt it was an unforgivable atrocity. The idea that there would be a static, single way of memorializing such a thing seems unlikely to me. But this is an aside.)

But he also notes that this was clearly not ultimately the case, that the sacrifices didn't add up to anything good. And he still says (at 13:18 or so) that he's not sure that people would see it as worth it.

Which is to say, it's not quite the remark you're making it out to be. It's very measured and admittedly hypothetical, and his couching it less as his opinion about what would have been worth it, and how people would have seen things in retrospect. He is essentially saying that if Soviet Communism had produced a utopia, the messiness of its early years might have been forgiven. But it didn't. So it can't.

Now, one could argue the point, and the interviewer does not seem totally convinced. But Hobsbawm is arguing about how people in his hypothetical alternate world might have thought about it, not how he thinks about it now. He is not justifying Stalin's terrors — he is carving out some space in why someone who believed they were making a utopia might have forgiven such a thing at the time.

I don't know if anyone reacted to this particular clip, but Hobsbawm's books have similar sorts of themes in them. He acknowledges the horror of Stalin but also acknowledges that Stalin industrialized the USSR and made it into a modern state. Did he face criticism for that? Loads! There have always been those, with various degrees of intellectual honesty (some are just anti-Communist cheap-shots), that have argued that Hobsbawm was too lenient when it came to Stalin and the horrors of the Soviet Union. Hobsbawm himself always replied that he did acknowledge and criticize these horrors, that he was no defender of Stalin, and so on, but how much weight you want to give him seems to depend on how much good faith you feel he was working with, and what one considers an appropriate amount of criticism fo Stalin (and whether one feels it possible to acknowledge anything that Stalin did as a positive thing). I don't know of this particular comment getting specific criticism, but reviews of his written work (and comments on his death) are full of these kinds of criticism.

I think it is possible to say that Hobsbawm's approach is very intellectual and serious, but also to say that for some, the horrors of Stalin are large enough to make any discussion of Stalin's "achievements" quite difficult, in the same way that it is very difficult to talk about Hitler's "achievements" with any kind of a straight face, given the magnitude of his crimes.

Updated edit: as an aside, I happened to read this fascinating NY Times article this morning about Gulag memories, and it is worth noting that even with the failure of the creation of a socialist utopia, Russian memories of Stalin are actually pretty favorable, and in some cases along the lines of what Hobsbawm imagines they might be: "He later put up eight wooden crosses at the site “in memory of those sacrificed.” But as a firm believer that Russia cannot thrive without sacrifice, he today reveres Stalin. “That Stalin was a great man is obvious,” he said, citing the leader’s role in defeating Nazi Germany and in turning a nation of peasants into an industrial power. Compared with the countless Native Americans killed in the United States, Mr. Naiman said, “nothing really terrible happened here.” ... An opinion poll published in March indicated that 76 percent of Russians have a favorable view of the Soviet Union, with Stalin outpacing all other Soviet leaders in public esteem." I don't endorse this, obviously, but it is an example of what a tricky thing historical memory can be...