Because he is capable of imposing his will in the fight, he makes them into wrestling matches and battles of "positional dominance". He doles out punishment, but it simply hasn't been spectacular. It's smart, but unpopular.
Georges St. Pierre is obviously a spectacular mixed martial artist, with perhaps the fewest deficiencies of anyone in the sport. His Kyokushin background keeps him fleet of foot; there's a bit of David Loiseau-Tae Kwan Do thrown in for spice; his boxing has been polished by the likes of Freddie Roach. While he isn't the most powerful puncher, he has a diverse striking attack littered with feints and constantly shifting angles that few opponents can defend.
St. Pierre's striking is largely used, however, in the setup of takedown attempts that succeed with wild accuracy: 80% of attempts were succesful in his last three bouts according to FightMetric . While his opponents are looking to seal up their high guard, GSP is free to seek a power double or get to the clinch and work for the knee-tap. When St. Pierre finally get's his opponent to the mat, he maintains a stifling top control with jiu-jitsu that can cut through almost any guard.
St. Pierre's overall game is sterling. But, despite his vast skillset he doesn't do anything that puts us on the edge of our seats. GSP's last three fights have all lacked a thunderous finish and, even though they were masterful exhibitions of a wide range of techniques, never captivated the audience like Fedor and Silva so easily do.
It's something that can't be ignored: Georges St. Pierre is a conservative fighter.
He wrestled down BJ Penn until breaking the fighter's will. The threat of the takedown allowed him to win a few exchanges with Thiago Alves before he inevitably took the game to the mat. Most notable, he did scant damage to Dan Hardy while holding top control and working for submissions.
Underserved or not, these performances have created a stench around GSP, that of being a "boring fighter". Ardent followers of the sport realize it's almost more important to be exciting than to be successful; it's why Matt Brown is still employed by the UFC and Gerald Harris isn't. Obviously, GSP is the champion and a face of the company, so he isn't going anywhere. But, it's not a steep drop-off to the level of a Jon Fitch, a highly successful fighter who would be ratings and buy-rate poison at the top of a fight card.
Against Josh Koscheck, St. Pierre could very well shirk this growing reputation that will eventually threaten his bottom-line. Koscheck will be a far tougher out in their rematch than the previous bout in which he completely disregarded GSP's wrestling. An NCAA champion, Koscheck could be nigh impossible to take down if he's been drilling hard at American Kickboxing Academy with the likes of Fitch, Daniel Cormier, and heavyweight champion Cain Velasquez. He is the rare fighter who isn't lapped by GSP's athleticism. Furthermore, his striking might lack the diversity and fluidity of St. Pierre's, but it more than makes up for all that with sheer power. At any point in the fight, Koscheck can turn the lights out for GSP if he lands cleanly.
I think this is a match where we'll see if Georges St. Pierre, the UFC's brightest star, can put on the dynamic performance we haven't seen from him since UFC 88 when Jon Fitch made him stand and strike. He won't be able to get Koscheck down with ease this time, so will he be hesitant to test Koscheck's power in a firefight? If GSP puts on a stinker in this one, it's highly likely his star will fade in spite of unparalleled dominance.