Those that can, do. Those that can't, teach. Those that can't teach, criticise.
In order of the above - management pilot, training pilot/instructor, check pilot/line pilot.
Some management and check pilots are on a power trip for sure, but so are a lot of ordinary pilots who adopt the 'captain' title (on the business card or in the phone book - seen that one, too). Some do it for money, some do it for the brain stimulus. Some are even smart enough to think ahead in case they need to secure an advantage when the poo hits the fan and they have to find another job. Everyone has their own reason.
If it bugs you, why don't you ask him if he was born an asshole, or just grew that way because of the job?