Not quite sure I understand what your question exactly is here. We all have people that for one reason or another causes us not to want to be around them but that's life as no one can please everyone out here but Life goes on. So avoiding this person is just self preservation at work and nothing wrong with it at all. If you're looking for a scientific answer as to why here, I hate to tell you that not everything in life has a clear cut black and white answer so you may not even really want a answer here. Just enjoy your life with all its good and bad and chances are that for just this one bad person, you probably have at least ten good friends so enjoy life's ride, as nothing lasts forever. Good luck