The people you play EDH with...
Generally when you go to play EDH/Commander this is what you would like to see, a large group of people playing and multiple opportunities to get into games. This allows you to play with new people and see different decks and learn different aspects of the game.
The above picture is what I like to call the optimal environment for options or choices. Different multi-player games and different play styles. If you don't like the people you are playing with there are many other opportunities to try other players.
What usually happens is that there are only a few people hanging out looking for a third or a fourth player to have a game. Many times it is the same people you play with every week and you see the same decks over and over. You learn peoples play styles and personalities (the good and the bad aspects). These games tend to boil down to playing against a personality rather than against the board state. I have seen this over and over again, and I have fallen victim to this mentality. Games then tend to break down to this.....
The blinders go on and you don't focus on much of what is going on in the game. Someone has painted a GIANT bulls-eye on their chest and all you want to do is get that person out of the game, board state be damned!
Personality has a huge impact in the way you are perceived by your playgroup and whether or not you want to play with certain people. I have witnessed this happen as well. Player X "My philosophy of EDH obviously doesn't mesh with yours, so maybe we shouldn't play together anymore," Player Y "OKAY, we won't!" Player X "Wait, what?"
Animosity toward other players because you feel that they do "Douchey" things every time they play.
What is the solution? I don't know if there is one, but if the perceived irritant continues then the continued use of blinders will probably continue. The other outcome is that players stop playing with each other until things can calm down, which I have noticed doesn't solve the problem.
I think this all boils back to this thin fuzzy line we call casual vs competitive. Mono Blue Slaver lock is never fun to play against, Uber ramp into Prophet of Kruphix and take a turn at the end of every turn not fun, Dead Eye and ETB all day long, not fun....
All of these things lead to my belief that people should check out other shops/play groups and get a feeling of where you like to play when you are in the mood for something casual or something more competitive. If we all just stay with the status quo of our groups and we have issues, EDH/Commander will stop being fun.
Remember it is just a game, let's have fun.