Well, Aristotle came not too long after. He had his own issues, but from what I've read, people took Aristotle more seriously. For instance, referring to The Philosopher meant Aristotle. Plato didn't enjoy a revival until relatively modern times.So much for enlightenment and the birth of modern civilization. Sounds more like central europe in the second quarter of the 20th century to me.
The Greeks did do some good things. The Athenians apparently debated the morality of slavery, and were at one point on the verge of banning it, when a war intervened.
In The Open Society and its Enemies, Karl Popper expresses a dim view of Plato.