You've never heard that Diogenes was a nudist and known for wanking in public? Or possibly even bestiality?
Also, I wonder what you think Socrates was on trial for. He called a lot of standard assumptions into question, and was called impious by the political/religious elite. They didn't like how he was educating people to think rationally instead of believing whatever they're told to believe, so they charged him with "corrupting the youth."
It's comparable to magas today going after public school teachers or college professors, because they teach "science" and other works of the devil.
A lot of people criticize Plato without really understanding him. They think he wanted a rationalist theocracy but that's missing the point entirely. He was against anti-intellectualism in a society that worshipped incestuous gods.
Also, Plato and Socrates made extensive use of elenchus and aporia, deliberately emphasizing the limitations of human knowledge. Instead of asserting what they believed to be true, they would use a series of questions to get their counterparts to examine their own beliefs, while identifying inconsistencies and irrational conclusions.
Their main thing was to point out how much of what people believe they "know," are actually assumptions based on societal conditioning.