There are so many combinations of possibilities in feelings and relationships.

I'm think back to my experiences. There was I was infatuated/ him not so much, he was/I wasn't, we both were attracted but there were reasons not to act on it. The only combination I never had was neither were attracted and we were just platonic friends, so you may be right about men not being friends with women who they don't find attractive. Or sometimes the man is the bf or husband of one of my gf's, and that is why we are friends who are platonic.

Why didn't you have sex with the girl you had such infatuation for when she wanted it?

Yes, I agree that you are right to assume her husband put a stop to your friendship.

I'm not really sure what you are saying or asking aside from my comments on your post.