Thats strange, I've found the Acolye very useful for dealing with corpse counters that my opponents Resurrectionests keep producing and using to get back everything I kill. Sure, he is in trouble if left unsupported, but I find with my marcus list, I don't need to leave him unsupported for very long at all.
I might not use him in all lists, but I struggle facing the continual hordes of undead someone like nicodem can put down if I don't have a way of getting rid of the corpse counters.
If you place him in the area you want the figth to be, and can get your crew in that area at the right time, I think he can be useful. And they need to send people to walk up to him to deal with him, they can't just throw a few shots your way whilst waiting for the rest of the crew to join. Don't use him until its worth him leavign his cover is my advice.