Good to see you back Wolfie. Missed you.^^

If WoW has taken measures to make the LFG better social-wise, that's great. I haven't played WoW since the start of Cata, and wouldn't know about recent changes. I was merely describing what can and did happen.

In entry-level dungeons, agreed. In the hard ones and heroics, does not happen.
Isn't that where it's the most important? Entry level is where people learn to play the game, and are introduced to the community, for better or for worse.

In two years of using the dungeon finder, scouring the forums, and talking with friends, I have seen less than 20 incidents like this. That number is minuscule when you take into consideration the hundreds of thousands of dungeon runs that are made via the dungeon finder, and is much lower than the number of inexperienced-yet-friendly people who get booted out of traditionally assembled groups.
Perhaps because you spent more time in the endgame groups, whereas I spent more of mine in the regular dungeons.