About liking to "fix" bad boys

There's is something about liking a bad boy, and him liking you. Something that has to do with the fact of being "good enough" to make him notice you and optimistically to make him settle.
If you find yourself trying to defend this guy to your friends, you understand me.
Let me clarify, he's not someone that treats you badly and/or cheats on you, it is the boy with bad reputation or with a troubled past that treats you right (most of the time), that confides in you.
Is this troubled soul that tells you they like you so much, and the next day tells you that they feel trapped in a relationship.
You see this good side when he talks to you and have a connection, and sometimes wonder why everyone talks so badly about him.
Well...been there...done that. And the conclusion is that when everyone says one thing they may be right.
Figuring out this complicated kind of men is not worth it most of the time, specially when they work to be very difficult to figure out, when they come close and then run away when they get scared, it is definitely a loose- loose situation.
Well, I've had a good experience with the bad boy that had a bad reputation of hanging out with too many girls, but having no girlfriend. I had him as a boyfriend for 3 happy years, why? because he wanted to settle down and he may have dated a lot of girls moving fast from one to the other, but wasn't a liar or a cheater.
So I guess it doesn't depend on the reputation, but on knowing the person and definitely on listening what they say.