I saw this a lot in the teachers I encountered in High School. Some of them were so incredibly arrogant. I never even shared things with these individuals or asked for their help because of how arrogent they were. I still can remember how they treated some of the other students that struggled. They acted like condescending bullies.

I often wonder if the reason some turn out the way you are describing is a result of being treated so poorly themselves. Often that's usually the case.