He may not be the most exciting, but he shuts people down. Say what you will of him, but he shuts people down. We can't act as though GSP didn't stand with Nick and give him plenty of time to get something going. GSP wears you down. He beats you at your own game. And he generally makes you look like a novice. He may not finish, and he may not take risks that would likely lead to him getting finishes, but he wins. And in the end, you don't retool a winning strategy.
I always tell people who accuse GSP of lay and pray that they ought to download a few Ben Askren fights. GSP constantly throws when he's in top position, as is evidenced by his opponents typically leaving bloody and bruised (as Diaz did). He just doesn't necessarily throw the hardest.
None of this is to say that GSP doesn't have off nights. I thought him very off tonight. It was as though he was fighting at 60%. But he still managed to beat Nick Diaz everywhere. So what do you tell a man who can run on half a tank and still make his opponents look like rookies? To change because a few punch drunk fans on the internet find him boring? C'mon.