Well, although i haven't studied the issue, it is worth noting that homosexuality is also practised by the god of beauty (and logic, order and other stuff) in greek theology, ie Apollo.
That said, it likely was not as common, nor as acceptable by and large as holywood movies or tv-level 'scholars' make it out to be. There is also the difference between accepting beautiful male form as something of worth and praise, and actually having homosexual relationship. For starters there were also negative ancient greek terms for homosexual, eg 'kinaidos', which literally means 'triggering shame'. (although i am not sure when it first appeared, it surely was there by early roman times, iirc it also is heavily used in Apuleus' travel story, "The golden ass" (as in donkey, you perverts
). I think in that story a community of homosexuals is banished and lives in a cave. The story is pretty funny, with a young person transformed into a donkey.
Later sources (eg Plutarch) present various things on this as well, but they are really many centuries after the peak of Athens/Sparta/Thebes/Macedonia. For example a story is about how (not sure if it happened; Plutarch was very openly pro-Athens) the king of early post-Alexander era Macedonia, Demetrios, tried to rape a good-looking youth in Athens, and the latter had to throw himself into a couldron with boiling water as they were in the baths.