Goals that people have when going into matchmade activities don't necessarily line up, and when they don't - someone is going to get frustrated. Nobody is happy about a person who tails behind in a strike because he's there just to explore weird corners. People farming strike bosses are unhappy about people farming solstice event elemental orbs from adds in the same strike. People farming elemental orbs are equally unhappy about people rushing to the boss. Nobody is happy about people leaving menagerie right after lamplighting because they got their 20 kills for Tribute Hall bounty. People can get into the same activity for a very different reasons, and because there's no way to disable matchmaking, they don't even have an option of being nice to each other. They are forced into the same queue.