If you keep it to yourself then that's fine..everyone is judgmental an that whole don't judge a book by it's cover is crap because everyone does it to some degree ..even if they don't notice it..but you might want to calm it down just a little..
I don't think that would make u a bad person you obviously know what type of people you would rather have in you life than others. In a way we all judge one another and as long as it is kept to your self you really aren't hurting any one.
There is a difference between condemning, or looking down your nose, at someone and being discerning about the evidence you see in someone's life. The Bible says it like this "be wise as serpents, but harmless as doves"