From Bendak on Eyes of the Beast:
Alright, I knew Survival would be the unpopular Hunter spec going into Legion, but I didn’t think the disparity would be quite this severe. After a week of Emerald Nightmare, the numbers are in and it’s not pretty for Survival. As I write this, there are ~48,000 Hunter parses in Heroic Emerald Nightmare on Warcraft Logs thus far. Only ~660 of those are from Survival Hunters, along with ~36,000 Marksmanship and ~11,000 Beast Mastery. Those Survival numbers are pretty appalling.
First of all, yes, not all guilds upload their combat logs (or even keep any) but I think in the first week the vast majority of them doing Heroic content will be doing so, and these numbers should be fairly representative of what’s going on. When you add anecdotal evidence about seemingly never seeing Survival Hunters in the wild, it becomes pretty clear: Hardly anyone seems to be playing Survival.
Survival had several things going against it, like the fact that most existing Hunters rolled a Hunter to play a ranged class and they have no interest in playing melee. Plus, existing melee players interested in joining the Hunter ranks may have had more appealing options in this department (the Demon Hunter or their existing melee class). There’s too many melee specs to go around…