every hunter that doesn't go BM for the stun is a failure.
tl;dr - Survival does more damage than BM. BM has more CC than Survival. If you can't land any kills as BM, even with that extra CC, then you are better off going Survival; because now not only are you not getting any kills, you are doing even less damage. You only need as much CC that allows you to get kills. Any CC that is left over could be better spent improving your damage. If you can't get any kills, regardless of how much CC you have, then the CC is irrelevant. If the CC is irrelevant, then the only thing that matters is your damage output.
How valuable is that stun when majority of players are playing their Paladins and Warriors? The stun(if the target isnt already immune) would only be valuable in a sense for it's interrupt. And if the target, who you stunned, is somehow not DR'd already; then you are going to make ur teammate's abilities DR.
1vs1, I would argue that BM may get better results than a Surv hunter.
But if we are talking about pugs, not 1vs1 or premades, your teammates are most likely going to be filled with Paladins and Warriors; which will either make your stun less valuable or it'll make your team's stuns less valuable.
I'd probably go Survival for pugs so that I can pump out lots of dmg and I wouldn't risk DRing my abilities with my teams. Hell I'd even run Moth/Wolf. Get the Crit chance, swap moth, and focus down a healer. Survival hunters are more than capable of putting a lot of pressure on a healer, BM just gives you more opportunities to land a kill with that extra CC. But you sacrifice that 1 extra CC for more damage. The difference may not be very noticeable. And if you can't even produce enough damage from BM to kill a healer in a 1v1 situation, even with that extra cc, then you might as well go Survival since that extra CC isn't getting you that kill anyways.
For premading, it would be debatable. With Coordinated CC, you would never have to worry about your CC DRing from a paladin or Warrior; vice versa. But if you are already running a heavy CC Comp in your premade, the Survival Dmg would look pretty good.
The less CCing your team needs to do, the more time your team has to pump out dmg. If your team already has enough CC to create openings for a kill, then there's no point to go BM. Hunters already have plenty of CC, go Survival if your team is not lacking CC. Scattershot + Moth Silence + Racial CC(if any) should be more than enough to land a kill. In some cases, that extra CC from BM may create more openings; but if you can't produce the damage for a kill then the extra CC is useless and now you do even less damage by using it.