My mom doesn’t like my friend because she doesn’t go to college

So I’m moving back into my apartment for the school year, I’m gonna be a junior in college, and my mom sat me down tonight and laid down some rules. One of them was that I’m not allowed to have my high school best friend over. I know that my parents don’t like her, what I didn’t know was why. And she finally said that she doesn’t like her because she doesn’t go to college. After high school, she started working immediately.

I was furious. I was so mad, because this girl is one of my best friends, and my mom liked her in high school, and now because she doesn’t go to college she’s a bad person. This is ridiculous. It’s disgusting to hate someone because of their personal choice. Not everyone can afford college, not everyone wants to go to college but my parents don’t seem to care. And I can’t even have a conversation about it with her because she starts yelling at me. I have this. I hate discriminating people or looking down on them, because they’re not in school or because of whatever. I’m not that kind of person. But now my parents are threatening to refuse to pay half my rent if I have her over.

What do I do? Am I being too much about it? It’s just that it’s not right, to look down on someone because they’re not at your level.