Why do roommates often scold others and say that people who cook deserve to be scolded?

He was aiming at you. It is estimated that you are inferior to him in some respects. He caught you and used it to laugh at you. This is often said to compare the shortcomings of others with their own advantages.

This kind of roommate has low moral character and is not a friend.

Don't be too kind. If you go back, you have to try to go back, otherwise, he will further degrade you in the future.