To us the idea of a monotheist easily accepting the idea of other gods, is ridiculous. The are probably millions of people around the world who would willingly die rather than worship any god besides God.
Did the Romans get that the jews felt that strongly about the issue?
The Romans didn't try to get Jews to worship Roman gods. Jews actually had special dispensation to practice their religion in Rome.
The Romans were actually very tolerant about religion and the name of the game was inclusion. On account of this, they found monotheism confusing or even atheistic. They had no problem with foreign gods, but they didn't really understand the denial of other gods.
They tolerated it in Judaism because it was ancient and because the Romans respected things that were ancient, but they didn't respect it in Christians because it was a new cult, was accused of secret rituals (secret organizations or religious practices were illegal under Jewish law) and was perceived as hostile and intolerant to other religions and gods.
They didn't really try to force them to worship other gods, but they did want them to honor the state cult - basically the cult of the Emperor - which to the Romans was not so much a religious thing as a patriotic thing. Somebody refusing to honor the state cult was sort of like refusing to say the Pledge of Allegiance.
The Romans didn’t try to force the Jews to worship Roman gods—Judaism was an officially-recognized legal religion in the empire since before Judea became a province. The conflicts between the Romans and Jews wasn’t over worship, but taxation and colonization.
Maybe you’re thinking of the Seleucids?