I'm definitely a guy, and I can tell you that every guy does not like every girl.
What your girlfriends are probably referring to is the strange phenomena that happens around 3am at the local club or bar, where drunken males tend to find a sexual partner for the night.
I don't think this has anything to do with them liking the girls they've slept with.
The reasons are more selfish if you ask me.
I think we're all guilty of doing this once or twice.