MMR Drop not bannable?

I reported a player and this is the message I got from GM.

http://i.imgur.com/41VFwbP.jpg

I was surprised I must admit. On the realm where you can barely get a que withing 15 min above 2k rate you allow this? Me and my partner just tried to do 10 arenas for weekly and after 7. or 8. time we called it cos no point. Good job.

If you have any complaints or suggestions to the GM team, feel free to send a PM to the head GM Aldtharios.
It won't help at all to have such discussion here, and as such I'll be closing the thread.