Rogan's commentary was shit in that fight. Khabib was piecing Iaquinta up with his jab and showing good hand speed and movement, yet Rogan never acknowledged any of the positive things that he was doing. If he were really as terrible as everybody is making out, then Iaquinta, who is regarded to be a competent boxer, would have been able to do something.
Most guys in the sport have serious flaws in their stand up games. I've never heard anybody get nitpicked to that degree when they were actually dominating the stand up portion of a fight.
And RE his wrestling in that fight, the stats basically mirrored his career average.
http://www.fightmetric.com/fighter-details/032cc3922d871c7f
Khabib doesn't have a 90%+ TD rate. His career TD accuracy is below 50%. He often gets stuffed on the first attempt but continues chain wrestling until he can get the TD. In a lot of instances, he doesn't even care about completing the TD because he can beat guys up and wear on them once he has control on the fence.
No shit he's not GSP. He's a completely different fighter with a much more diverse TD game, and he cares more about getting a hold of his opponent than positional control on the ground.