I am actually part of a community called Scared of Dungeons ((Alliance) Scared of Dungeons EU EN).
When I go for an m+ I first ask from this community and then get pugs. Members here are people who are not so good at tactics (including me) or tolerate others not being so good at tactics, and usually an ilvl that is considered low in pugs (if you look my toon up, you can see I am definitely a casual player). But, they do not flame/bash/call each other names and will stick out a dungeon run for 2 hours because they care about having fun and not about raider io scores.
None of these people are hopeless, but they definitely need some explaining of the tactics and a decent amount of tries to practice the boss before we finally down it. And I am happy with that, really.
The mentality is so different and refreshing and I just wish this could be a bigger thing than what it is currently. Wow is suffering from toxicity because people with different mindsets collide. They should be separated somehow.