Actually, it has nothing to do with pandas. What makes me dislike MoP, was the garbage quest writing and boring zone design (Jade forrest and the 5.1 solo questline were the only positives). Raids were mediocre, with the exception of ToT and endgame was a swarm of dailies. The best thing to come out of MoP was the fun I had with my warlock main.
So no, the pandaren were the least of my problems with that expansion.