Why Do Guys Fall In Love With Girls That Are Skanks & Treat Them Bad Instead Of Girls Who Treat Them Well?

I don't get it. And hotness is not a factor because his recent ex (the one he is so lovesick about because he fell for her) is not hot. And, as unconcededly as this can sound, I am a lot more attractive than her...so that's not the reason. I treated him so well, but he never fell for me, but he falls in love with this girl after a month and she's a skank. WTF?