I don't think that's true. A genuinely good person, who is ideally not only a good person but also has his shit together in life, does not have a lot of trouble in the dating world.

There are some guys who kind of lack personal boundaries, who are altruistic to the point of being "pushovers", i.e. they let their own life suffer under their need to appease others. Who can't say "no" basically. That's not really the same thing as being a good person.

And of course there are certain kinds of girls who only dig the macho stereotype, who mistake abusiveness for "manliness" because it's all they've ever known. But this isn't true of mentally healthy women with more self-esteem.

I think these two cases are where the "girls are into assholes" stereotype comes from. Of course you need to take sufficient care of yourself, not just of others. And of course there are some girls who are "damaged goods" and who really do need an asshole (or think they do). But aside from that, it's just not true.