This all stems from the fact that you really only need like 18 people to do WoD, 15 or so to do ST, and like 12 or 13 to do LotA, so its really really easily missed if someone is just doing nothing. They aren't trolling you they just want stuff and also want to read the news, watch TV, BS with their friends, or do whatever else. This is just a design issue enabling assholes to do nothing. And, if I am being totally candid, its because most people suck really bad at this game. They had to make the content so super easy and thus doable by 24 people who aren't so good, that a much smaller number of good players can do it. For every 2 good players, you can probably have 1 character removed from the instance and be totally fine.