> the user, holodeck style, describes what they want and it is assembled in front of them.

I really don't think this is what most gamers want - and I think they'd like it even less if they tried it, for the reason you highlight 2 sentences later...

> The valuable part is a talent for creating gameplay systems

Beyond that, gamers like a sense of "community" - being able to talk to people who play the same game, have a shared framework for achievements and the like, etc.

I do believe generative gameplay will be the next big thing, but not to spit out an entire game by any means.