Well why not? asks Sean O'Neal in this AV Club post that is not only funny in its own right, but links to another funny post by the same Mr. O'Neal. The latter piece is about pointless Star Wars 7 speculation by an ex-employee by the name of George Lucas. The former is about how Warwick Davis (and dozens of other Star Wars alumni, most of whom have enjoyed far less success that Mr. Davis) would really really like to be in the new Star Wars movie.
If even a quarter of these faint-hopers end up in the new film, it will be worse than Attack of the Clones.