The big question is to what/who was Tolkien alluding. Nearly everything in the book has a parallel to Catholicism or to WWII. My take has been that Tom Bombadil was a reference to Switzerland's actions (lack thereof) during WWII. A power that was strong enough to be immune to the Nazis, but without the interest to do anything about them. There is a certain nobility about him, and yet the Elves know they can't count on him for help.
If I have understood Tolkien's intentions correctly, I consider his character to be brilliant writing, but of course, there are many opinions about what he was supposed to represent.