Ahhh. The age-old question: "What is she doing with that creep?" which I can just as easily fire back at you with "Why does he put up with that bitch?"
I don't think any single girl asks her friends: "Hey, does your boyfriend know any losers? And if so, are they available?" The fact of it is that we do want nice guys. And it would be terrible if all the nice guys thought they had to become assholes to get the girls they want. I'm telling you now: they don't. I am sure there are a lot of societal factors involved that affect the wrong choices girls (and guys) make. Things like the relationship their parents had, the way they were treated by their siblings, how their friends were treated by their significant others. Or good old denial. Even the brutes are charming, even sweet, at first.
Now I admit that for some of us, the bad boy holds a certain allure. Smart women realize, sooner rather than later, that the qualities that make those kinds of guys exciting are what make them bad choices for long term relationships.
Inconsistency sometimes keeps people hanging on; too nice = *yawn*. Too mean and they'll beat it. But sometimes nice, sometimes bitchy, and you'll keep them interested.
But my advice to you is to treat people the way you wish to be treated. Boring, but golden. I can't think of a single reason why you shouldn't be respectful to everyone. You know that song "Praise You" by Fatboy Slim? It always puts a smile on my face. That's copacetic.
à tout jamais,