I don't think it's that uncommon, actually. Plenty of players in the NBA are more concerned with the lifestyle and status that comes with being in the league than with actually being a consummate professional. Harden just stands out because he's so good, but honestly you can probably run down most rosters and find a couple of guys who's passion for the game is lacking just as much as Harden. They just aren't under a microscope bc they aren't top players. I think even most players that have shown professionalism, passion, and a desire to win are still concerned with the fame and status that comes with being a pro athlete (guys like Wade, Shaq, Kirby, Parker, Donkey, etc).
The rare ones are guys like Tim, Manu, Dirk, Kawhi who dedicate their lives to the sport and seemingly don't give a about anything other than being great at their job and winning.