true male-female friendships are actually very possible.
the problem arises when one party realizes what they have going on, and thinks to themselves "hey, l actually really get along with this person, why should I keep struggling with the dating market?"
that's usually the man, but sometimes it's the woman.
in any case, the big question is: why is this such a problem? shouldn't this be the goal? if you want a fulfilled life, shouldn't you want to end up with one of your friends, who already valued you as a person, before any horniness got in the way?