Chicks that aren't fukking each other tend to let jealousy/aggression undermine whatever sisterly love they either had for each other or claim to on social media; with all them cheek to cheek fukking selfies.
Plus it's easier for a chick to hang with a dude because she knows he ain't trying to either fukk her man if she has one (shyt should be limited to group interactions with other friends as opposed to one on one shyt) and ain't talking about whatever faults or bad traits she has to other female friends (Dude might more than likely tell the squad but she don't care most of the time).
Plus chicks love to compete with each other to see who's life better or about to get better with plans they make (Going to school, applying jobs, having kids, dating dudes about to make it big etc..) for the short and long term and that ratchets up the jealousy factor for the girl that's losing. Long story short, alot of these women hate being in competition with chicks for and about dudes so they eliminate 'em and just hang with dudes and start choosing without any interference or competition.