I know this is not always the case, and there are exceptions (though few and far between). One of my close friends is actually currently being pursued by a guy who is making every effort. It's super cute. Unfortunately she isn't really keen, but still, I commend his efforts and respect his determination!! And you never know, all his efforts might just pay off in the end.
I wish we could go back to the days where guys took girls out to dinner and the movies and bought them flowers and made all sorts of efforts to win them over. And I don't think it would be too hard to get back to that, cause if a guy really likes a girl he will make an effort. And if girls weren't so loose then guys would have the opportunity and motivation to do so.