That's not what he's arguing. He's saying because people aren't playing optimally, in whatever content he was doing, that they're harassing him because he has no recourse. He can't kick them for poor performance, he can't kick them for wasting time, etc...
But with that said, I won't pretend that the performance of the group doesn't have a pretty significant impact on how long it takes to complete it. @
Wrecktangle has been on multiple times showcasing just how different completion times of dungeons can be based on group performance. A fully optimal group doing everything "right" takes ~10-12 minutes to complete a dungeon, whereas an unoptimal group doing a lot of things wrong will take 20+ minutes to finish. That's a significant difference. Is it life changing and enough to get THIS bent out of shape over? Not in my opinion no, for a few reasons. 1) it's minutes of your life spent in a game you're supposedly playing to enjoy. Shouldn't be THAT big of a deal, but most importantly 2) If you're using the RANDOM duty finder you will be placed in a group of random players with random levels of skill, ability, etc... it's a completely unreasonable expectation to think you'll be getting optimal performance from that kind of group consistently.