Gotta love the good old pax Romana.

N.B. Up until Constantine, religion was not generally an issue under Roman rule (Except the druids... nasty seditious human-sacrificing people that they were. The human sacrifice was distasteful - but their propensity for spreading dissent was the main reason the Romans went to such lengths to crush them)

Also, try as I might, I can't think of any occasion when Judean Zeolots embarked on an empire-wide slaughter of Roman citizens... I will give you that there were 2 more revolts after Titus (well, one set of riots and a major revolt). '580,000 Jews (mass civilian casualties), 50 fortified towns and 985 villages razed.' in Bar Kokhba’s revolt, According to Cassius Dio via Wikipedia. They were not exterminated, but nor were they let off lightly. I don't see any mention of a Jewish revolt after that...

Basically, what I'm saying, is that people are thick. And sometimes, something heavy is required to hammer the message home. But as long as they feel that they can act with impunity, people will. Why co-operate when you don't have to? Much like training an animal, people as a whole need to be forced to behave in a certain way before they do so voluntarily.

Gods I despise the human race.