If its just to keep someone's name in the mind for later stakes, some of these players need to not share the bust hands, because 95% of the time they are junk and makes a potential staker question their ability as a player.

As for the about 80% that post hand by hand plays, it's pure arrogance, at least in my mind anyway. There is a small percentage of people who post, like Poof said, just to satisfy a question or who just get wrapped up in it. I do think that some of it can just be the excitement of the game, I have to admit I have done it myself with a few of the tourneys I have played, emphasis on FEW.