Why do guys always treat mean girls like princesses and nice girls like doormats?

I don’t need answers like «yeah! The same way Girls go for bad guys». I have seen a lot of Nice, pretty, caring girls that tried to stay with nice guys but they always leave them for a woman who obviously has no "good" quality. She is considered selfish and not really appreciated, especially by other women.
In addition, this "witch" is not even really pretty.
Oddly, this kind of woman often manages to conquer the man of her dreams.
The problem with these guys is they spend up to 30 miserable years in a stress filled marriage with a mean girl that usually ends up in a divorce bitter. After that experience they are ready to give a nice girl shot.

However, by the time these guys make a mistake, the girls want nothing to do with them. They are fed up with being touted for being “too nice” and would rather be able to do anything with an uncompromising clueless guy who only sees a backup plan.
Why do guys always treat mean girls like princesses and nice girls like doormats?
Why do guys always treat mean girls like princesses and nice girls like doormats?
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