I think that view is an overcorrection to their inflated reputation. They, like every other Classical Greek state, had their comparative times of strength and weakness.
That, supposedly, is a bit of misinformation spread by NAMBLA types. The Greeks apparently didn't care for too large an age gap in pederastic relationships, and 16 was roughly considered to be the socially acceptable age to begin one.
Not great by modern standards but certainly better than some, and better than they treated women who were often considered marriable at 14. Though at least that was better than the Roman 12, and Aristotle even argued that 21 was the most appropriate age for healthy children (fertility periods being their primary concern)