Do you think I'm wrong for not wanting my parents to adopt?
Without a reason I can't really answer that. Why would you wish for your parents to not adopt?
They are not the best people in the world, I don't think they deserve to adopt.
Although adoption is a very good thing, not all people are suited for it. If you feel that your parents would be bad adoptive parents, you can sit down with them and explain your feelings. Just be sure to do it in a way that is respectful and kind.
But I want to see them suffer from all this.
Having legitimate concerns about your parents adopting is fine but if you're doing this just to make them suffer then I think the real problem is with you. You shouldn't hold so much hatred that you would wish for someone to suffer. Find a way to move past that feeling and you'll be much better off.