You get a very clear resolution to the film. I maintain that the ending is as perfect as it can get for this story. There is only one possible outcome to one man vs. a pack of wolves, and it isn't guy kills all wolves then a rescue helicopter flies over and everything is just dandy bars. The film ends with Ottway being done with running, making his stand, and knowing full well that he's done. But he's going out on his own terms. Not drowning in a river or falling off a cliff. Once more into the fray. That's the resolution, not something as pat as whether he gets rescued or not.
The main problem with The Grey was that it was marketed as Liam Neeson vs. Wolves, and that's not what it is at all. Just because the premise and some of the events of a film are preposterous, it doesn't mean the film itself was. There's not a lot of films that have genuinely realistic premises and characters. The characters are developed enough, it's just in a much more subtle way than most films. I didn't find any of them to be stock character like you might think you'd see in a film like this.