Sure, I agree with that. I guess people don't want to be in a position of having to choose between freezing to death and going bankrupt. So they won't go with the spot-price following contract, even though in some sense it would be better for the grid as a whole.

I suppose this could be handled with some kind of roof price (with the lost money being inserted as some kind of fixed surcharge on the bill or something like that). That would allow reaping most of the benefits of spot pricing without risking bankruptcy during a crisis.