"If we're going to argue at all, our position should be that play is potentially as important as art, if not more so."

I think that's an interesting point to make. What does art bring that play doesn't do so more?

Play has, for centuries, been the way of passing down history via stories and songs. It's been part of culture so much more than mere pictures, which can be destroyed.

While you won't be popular because of your stance against games being art, hopefully people won't stop before the end of your comment and will ponder this point.