"Oh no this guy is a lot stronger than I am...well screw it I'm going to go watch the Biggist Loser!"
I admit, the hero always standing up and using his once uncontrolable power is a clishe (cleshae, che...whaterver) as old as time itself (who can forget when Jesus finally mastered the 100 arc kick and beat Moses at the 107th Habatchi Tournament) but it is a nessesary plot device to keep the story going.
That said, yeah Naruto is getting a little...off as of late, but maybe whoever writes it is getting tired of it... think DBZ