Kevin, I'll tell you why not. Because the existence of the game you mention was due to an error by IYT as a result of their not realizing the right way to set up the game. What you are saying amounts to this: "People are used to playing it the wrong way, so we should not correct the error."
To me, I just don't think that is a good idea.
Yes, webTV users need the 13 X 13 board. But why not rectify the error IYT made by at least keeping the restriction on the 13 X 13 board?
Incidentally== non serious players are affected also, because even non serious players like to play the game with the correct rules. I have encountered non-serious players at DSG who were frustrated to have learned the game with the wrong rules as a result of what IYT did. So, it is not just the serious players who were affected.