You are forgetting that morality is not absolute. It fluctuates over time.
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.
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.