What in your experience are the specs that seem to have the most retarded players? In BC it was easily BM hunters and combat rogues. In WoLK, ret pallies and any death knight.
Now, it feels to me the specs that suffer most from dumb and unskilled players are: ret pallies, boomkins, prot pallies, shadow priest, arcane mages, frost death knights.
Edit - might be overly hard on boomkins and frost death knights since i play both of those classes, and cant help but notice when nearly every pug mangles such simple rotations,