I think the problem is that most games Horde is getting an excessive amount of healers while alliance isn't.
I was really surprised that we won this game. Even though it says there are only 4 healers on Horde, there was actually 5 for the majority of the game. Heezow wasn't in there the whole time, I know that Trashcat afked towards the end. So it was actually 5 healers; 3 holy paladins and 2 resto druids. If you look at scoreboard Heezow doesn't have much damage or healing done. I even got off a 1000 ish execute on someone and they still lived because of all of the healers.
Thanks to geno for carrying my fatass in this game, I know I'm really heavy.