Lots of women only really have a pussy to bring to the table.
Think about it: you're friends with a woman. Even if she's cool you can't treat her as one of the boys or society will grill you.
So you're left with "less than a male" friend.
A guy is almost always better off having a good male friend vs a good female friend.
A woman is ALSO almost always better off with a good male friend than a good female friend.