For me, I quit this game because I mained Holy Priest since the end of Wrath and quit about half way through Blackrock Foundry. I quit because Holy priests were literally being pushed out of raid groups. If you already had a disc priest in the raid, you didn't need to swap to disc. I hated disc healing. If there was any other kind of healer, you were swapped out for that healer because they could heal better. It was really frustrating and in turn I just quit because I only played wow really to raid. I found that to be the most enjoyable thing about the game and it was taken from me because Holy Priests were shit now.
If Holy priests become a great healer, a healer that everyone wants in the raid because of throughput, I'll come back. I'm glad disc is getting fucked over, but I'm still questionable on who will come out on top. We will see.