i really wonder. . . . .

I really wonder sometimes what it is about Men that make them act the way they do? Is it that they can't seem to diverge from their natural habit or is it that they just act that way b/c some women let them?
I've been involved with this guy for quite some time and I just don't see the point anymore. In the past several months I have not really gained anything from this relationship whatsoever and the more I start to think about it, the more and more upset I get. Alas, I have a strong attachment to him and it is hard for me to leave him alone.
sometimes I think that it's my fault that he acts the way he does and then I realize that I haven't done anything to deserve such treatment. I realize that I deserve so much more than unreturned phone calls, trips to PP to get 'Plan B,' and just not being appreciated. I am such a kind spirit but I seem to continue to fall for the same type of Men.
About a year ago, I came to conclusion that I don't trust my judgement and my taste in men. It seems like all the characteristics that I find attractive just don't "tag along" with all the good qualities that I need from a Man. I also came to the conclusion that I go through all of the things that I do for a reason. So I really can't get mad, but I must admit that I am quite tired.
I'm writing this b/c maybe just maybe there is someone who feels the same way I do and maybe reading this will save them from getting into a bad situation with a Man who just is not right for you.