This is my point. Galileo didn't advance knowledge by his acts, that was already done (within the scientific community if not within the wider world) (And granted, he did advance knowledge at other times on other subjects). He attempted to use it to change the state by agitating large portions of the population using that fact.
I would even say he was not so much looking to change the state, rather to destroy it, becoming a sort of dictator himself, without any thought to what that would do. This he did after a few years of sending out letter that made it very clear he would immediately execute half the nobility and clergy if he did come to power. It didn't help that he had pissed off all of his teachers and environment with those letters. This is what his trial was really about, and of course it mentioned his rallying cries.Those were not the essence of the trial though.
Think about it. Suppose you're an autocratic ruler in the middle ages, in Italy. Everybody's writing letters, a lot of them calling for your throat getting slit. One more of these lunatics starts writing letters. Disturbing letters, lots of them. You ignore him, at this point, there's 100 others like him. Then a few demonstrations happen, led by him, with hundreds of people calling for your throat getting slit on the street. This is unnerving, but happens regularly, most demonstration leaders are never seen again, so, again, you probably ignore this. But if he manages to make the demonstrations grow, you've got to react. That's what happened.
Regardless if you agree with the second paragraph, he was not attacked because he claimed the earth rotated around the sun.