Actually I agree with the courtesy of the F/O waiting for the Capt to exit first. It's just good old fashioned manners, nothing to do with egotism at all. I always did it as a co-pilot, and didn't have to be asked or taught. It just seemed right and proper. Nowadays nobody gives a damn about etiquette, least of all the spotty youths in the RHS. I even had one of them recently get up in mid flight barely grunting 'you have control' and leaving the cockpit, without as much as an explanation or by your leave! He was off to the bathroom, and why should a big boy like him have to ask permission?
Why indeed?
Idiot.