To be honest, Gareth, I believe you when you say men and women think of friendship without opposite differently.

I have watched several interviews with besties of opposite sex and the guys in the "friendzones" fall in love with their females besties more than the women.

And like you said, guys only keep women they see a future with as beaties while women keep loyal friends as besties. When I think about it, this could explain why women hardly fall in love with the male besties.

The women just want a friend they can count on anytime and because the guy is in love with her, he does anything she says unconditionally.