Basically the crux is:
Say you take a person with a performance orientation ("Paul") and a person with a mastery orientation ("Matt"). Give them each an easy puzzle, and they will both do well. Paul will complete it quickly and smile proudly at how well he performed. Matt will complete it quickly and be satisfied that he has mastered the skill involved.
Now give them each a difficult puzzle. Paul will jump in gamely, but it will soon become clear he cannot overcome it as impressively as he did the last one. The opportunity to show off has disappeared, and Paul will lose interest and give up. Matt, on the other hand, when stymied, will push harder. His early failure means there's still something to be learned here, and he will persevere until he does so and solves the puzzle.
I'd put myself in the mastery category (not that I ever really succeed though) if a game is a challenge it's instantly more appealing to me than a game where the difficulty curve is not steep. I'd pick a highscore based game over a story based RPG any day.
I heard a good quote there the other day regarding Street Fighter IV, it went something like "In RPGs the player levels their character, in SFIV the player levels themselves".