When Tiger signed his contract with Nike, he wasn't bound to any club contract because Nike didn't even make golf clubs at that time. Tiger was able to gradually fit them into his bag when Nike started making them.
Rory on the other hand is bound to a club contract. He like many many PGA pro's were set up with Titlest clubs and they catered to his every need as far as clubs & took damn good care of Rory. I find that the most used (that I have noticed) clubs on tour are Titlest. Titlest makes the best ball on tour in my view.
So the equipment change is responable for the poor play to a degree imo. And that can get into your head.
But it's like Nicklaus said the other day about Rory "A carpenter doesn't blame bad work on his tools"; Pros have to adapt to different equipment for instance the different size ball on the Europian tour and such.
Rory won a U.S. open by a landslide. I highly doubt we have seen the last of his wins.