I wouldn't be as harsh about it, but I agree in a way; This game / world / story has been released to the public, and it takes on a life of it's own once that happens. I don't feel bad AT ALL for him, in that he's found a dedicated fanbase that WANTS to see more of his world, characters, concepts, etc.
It's probably one of the best problems to have. "Oh No, people pay enough attention to my work, to actually wanna chime in, and care about what direction it goes!" Boo Hoo?
Make the fans happy, and you'll be telling your stories through a mass of constantly selling media, games, books, etc. Stick too close to your non-altering, rigid vision, and you'll trivialize each chance you get.
Mixing the fan and creator visions turns into a much healtier, interesting product. Too much of either, once it's out there, can very easily kill it.