Okay, this talks a lot about the ending of 3:10 to Yuma, and I'm not planning on talking about things explicitly, but if you're worried about it, don't read.
I've been reading some reviews of the movie, and all the questioning the reviewers were doing (most were really positive, this is just from a small portion) seemed to be focused on the ending. Unrealistic, illogical, sell-out, poorly plotted, "left its cowboy logic back at the station," were all things mentioned. Now, correct me if I'm wrong, but this is more than just a shoot-em up movie. The characters' motivation was not anything simple. The things that happened weren't illogical, but done on purpose as part of the character development. And certainly not easily understood. I honestly think that people who watch this movie and come out with conclusions like that about the ending must have really not been thinking at all. And maybe they should go watch Bad Boys II.
<--zing!!
So, it just sounded to me like those who were criticizing it were only looking at the face-value half of the movie, and didn't even see the other half of it where the ideas weren't spelled out for them. Sillies.