Men get rejected actively more because they take action more... But many women - especially young ones - consider not being approached as a rejection as well. In a way, guys can choose if they want to risk rejection each outing, but young women often feel that if they aren't noticed, they're rejected by default.
I'd say a mix of both. I'm not the type of person to go out of my way to approach a stranger and try to date them. I gotta be friends first before I would even consider dating someone. But from my experiences i see so many of my friends reject girls for relationships.