Are you aware of how many homophobes there are in the older generations compared to the millennials? Or ignorance in general? It doesn't even compare.
Judging older generations by today's standards isn't really any different then them judging you by their standards.
I'd say Thomas Jefferson was wrong for having slaves. Granted, that was bad. But if he had a time machine, he'd probably point out all kinds of moral blind spots in my generation.
It's possible that in the future, homophobia may become the norm again in developed countries. People in that era will look down on us as permissive degenerates, just like we look at 19th century people as intolerant bigots.