Well, its just plain bad strategy in his part. Yes, they are useful, versatile techniques, but he has used them so much that EVERYONE KNOWS about them. Any ninja worth his salt will have developed a counter to the attack if they know they will be dealing with Naruto (like, say...a group of shadowy ultra powerful badguys with plots of world domination that hunt people possessing tailed beasts and forcibly strip the monsters out of said people). So the techniques are only truly useful if Naruto takes his enemy by surprise and has never dealt with them before. Old enemies like Orochimaru and Kabuto are sure to have already created strategies to render those techniques useless.

Just my two cents. ::shy grin::