To quote JMS replying to fans criticizing the final episode of Babylon 5:
Dear Mr. Tolkien:
I just wanted to say that I think the way you ended THE LORD OF THE RINGS was crap. You didn't provide any closure. Instead of spending time with the hobbits clearing out the shire (come on, urban renewal in LoTR? give me a break) and lots of goodbyes, you SHOULD have shown me what happened to Tom Bombadil, he was an important part of the story, and you just left his story thread there, unresolved.
You made a big deal out of the elves going to the west, but we never SAW it! We never found out what was there, or what Bilbo found when he got there, or what happened to the dwarves, or what happened to Merry and Pippin....
You betrayed your audience by not resolving every single plot thread you introduced in your book, and as a result, it is never going to be of value to anyone, ever, and will never go past its first printing.