You don’t need to identify the people you don’t want to play with. You need to identify the people you want to play with. Yes, that is harder. Yes, that is more time consuming. If you care so much, then you should be willing to put in the time and effort.
This has also been gone over many times in multiple threads. Just because I have a steady group now doesn’t mean that was always the case. I’ve played the game for over 11 years in many different ways. I’ve spent plenty of time in pugs, I’ve spent plenty of time in guild raids and dungeons. None of this is all that complicated and I understand it just fine, thank you.
What you can’t seem to grasp is that group activities don’t come with guarantees of success, and you don’t get to tell other people what to do with the time they are paying for. A M+ dungeon may fail, and someone may leave. That’s life. There are a ton of different things you can do to try to mitigate the risk of either or both of those issues. Do them and stop begging for Blizzard to manage your social interactions.
That is the issue, and if you can’t understand it then maybe you should spend more time reading and less time trying to send smarter people out of the discussion.