I'm going to throw my roommate's plates away
Why would you destroy someone else's plates?
Well if he doesn't eat what I cook him I am really going to be offended.
If you cook for someone you expect them to be nice about it, but to destroy their property if they don't is uncalled for. Ask them what you could do to improve, that will be more productive than so much anger. If you cannot be civil then I guess you should just cook for yourself.
I don't care, I could just get a new roommate using my parents money.
If that is how you feel why haven't you gotten one yet? People have their own likes and dislikes you know? Maybe ask them what kind of dish they would like for dinner before you make it.