Heh, Perhaps you're right about the reason that Tolkien's works are so popular. Honestly, I like his elves better than I like other elves, but that's perhaps because I was introduced to Tolkien's elves before I was really introduced to any other sort. Even now, I don't have a very firm grasp on the more usual sort of elves. Only Santa's elves and Tolkien's......

And why not borrow a fantasy world? The reason I make up worlds and histories is so that other people can borrow my worlds, and make their own histories to interlock with mine. To see someone using my world pleases me no end. And to borrow someone else's world (mind you, I do usually ask first, if possible) is a great thing for me.