There have been several posts and discussions recently on several book blogs I read about literary fiction having unhappy endings. I think Return of the Native makes an interesting point about this though, since it has a happy ending tacked on to a rather unhappy story.
The trouble is that ending doesn't fit with the rest of the book. It doesn't make it into a happy book, and I don't think it's particularly realistic. I certainly don't like the book better because of the happy ending.
I've said before that fiction is an escape and that's why I like to read it, but that's not quite right. Fiction with a happy ending is an escape. Fiction with a sad ending is a lot more likely to make me think, and that's really why I like to read. That's why non-fiction is often so good. Of course, there's plenty of entertaining non-fiction though, like Bill Bryson. His books are an escape.
So I guess the difference for me is that there are books that make me think, and books that I simply enjoy. And I like to read both. Sometimes even at the same time.