I guess the main reason people treat the one who respect them, is about their parents, mostly.
They don’t like themselves. They were born and raised with disrespect. Usually their mom hated their dad. They treat others terribly because deep down they are insecure. They are sure no one likes them, and that they are not worthy. So if someone likes them or respects them, it’s definitely a negative sign, meaning that the lover is probably worthless person. Because no worthy one will ever like them.
There is another reason, however. These people are usually sociopath and sadistic. When they find someone who cares about them, they find a chance to take of advantage of that person and hurt them. They enjoy it. It’s their personality trait.
That’s why there is no winning with these people. That’s why you should avoid these people. Once you move on and finally find normal and sane people, you figure what monsters those people who surrounded you were. There is a reason they struggle. Not every struggler deserves that, but these people definitely do.
The country I came from, had many of these people. You could see a 35 year old guy and think he is mature, but no. ،They were immature, remained immature, and will die immature. People never change.