Well that is what I call the "Gladiator's Syndrome": at the first loss (no matter if you did 300-0) you disband istant the team, rage against your teammate and log out (or look for another partner).
That behaviour sucks for sure, but add the fact that now you get points only by winning, on Blackrock, who else could be motivated to win 10 and loose 15 everytime because there is no MMR, everything is hidden, nobody knows what's going on on rating decision after matches..? Tell me who would be entertained and stimulated in playing arenas when points giving system is completely random.
In fact I discovered if you are below 1500 rating, you can get even 30 points if u win!!! 30 points!
But once you are over 1500-1550-1600, you can pray 40 different Gods and I promise you that you will NEVER see more than +10 for a win. It doesn't matter who you face and what rating are them. (Or what's their MMR, IF there is a MMR...because -lol we hide the mmr for who knows the reason-)
Again as said in another topic and I didn't receive a reply: WHY is the mmr hidden? Whats the official explanation of hiding the rating? You think hiding it people will stop wintrading or other stuff? Im pretty sure you don't need to HIDE the mmr at the end of the arena to demotivate people to hack, just make that if a character leaves the current team arena and joins another, his MMR resets from zero (or 1500). Is it so hard to script? I really don't get this...