It's to determine the best chess player in the world, not to be entertaining.
I thought it was supposed to be both. I haven't watched any of it because chess at that level is so boring, but isn't the whole purpose of people watching, TV cameras, reporters, spectators, etc. entertainment? Aren't games specifically designed for entertainment? If it's not entertaining, why watch or participate?
I think a 12 game match is a bit short when comparing past world championship matches.
If 12 games, then instead of the current tiebreak system, how about the first player to win a classical game after the 12 game mark.
We all know the horror stories of the 6 month long (or whatever it was) Karpov - Kasparov match.
Not that I dislike your idea. I very much like an indefinite game limit like that, but I think the hurdle there is money. Players want money which means sponsors, and sponsors (for one reason or another) don't want a 100 game match.