Whatever the reason, in Hollywood, it's the the girls want.
The "bad boy" targets the strongest womanly instincts: the stoic, silent guy is a mystery waiting to be solved; the Troubled, but Cute youth with a tragic past is a woobie needing comfort; he's tough enough to be a girl's protector, but vulnerable enough to need her as well.
It all depends on what the author wants to use this trope for.
My most recent mistake took the form of a middle-class technology software partner who wore J Crew.
He didn't have much in common with my first bad boy at all, except for one thing: the way they treated me. We are enraptured by their spontaneity, by the excitement and anticipation of being with them.
My first was from a chaotic background: brought up in foster care, a school dropout by 14, eyes the colour of caramel latte.
But being a bad boy isn't about being from the wrong side of the tracks.
Add to that the fact that Evil Is Cool, the Anti-Hero ranks as Bachelor of the Month.