Leave (the instance) . Your experience is in your hands. Expecting others to perform to your standards (even if they're reasonable) is still entitlement. People buy the game and buy boosts, or their friends run them through PoTD till they're 70. Lot's of people have neither time nor inclination to learn to your standards. This isn't a job. Nobody is forcing you to experience anything you don't want to. You want standards then as someone else said, gather like individuals. You do roulettes then expect casual sprouts. Also I rarely experience someone who is nearly as bad as you say. Sure there's some dead weight out there, but people who do bloody edge extreme content and don't know basics are quite rare.
You are not who gets to decide what's "acceptable" by yourself. If the majority of the playerbase is OK with it, why do you need to bring intolerance into the dungeon? Who's the odd man out when you're the only one tearing their hair out over it? People play this game for many reasons that don't align with yours. You get to customize your own experience and the fact you think you have the right to dictate how others enjoy it any further than a helpful suggestion or removing yourself from the situation shows a certain degree of selfishness and entitlement in itself.