I'm not on a wholesale rate plan, but if I was, you can bet your sweet ass that I would be A. monitoring the wholesale price B. switching off my main breaker the moment the price went above $X.
As such, don't really agree with the conclusion of the article. We mandate having car insurance not because we care if you can't afford to fix your car when you wreck it, but rather because if you crash into someone else we don't want you to dodge paying for what you've done to them.
Electricity is entirely a you thing. Your neighbor/society doesn't get hurt if you use Griddy with uncapped rates, only you do (and as pointed out above, you can avoid this if you're smart). Yes people will get burned, but I don't want to live in a society that tries to prevent people from ever making personal mistakes – mostly because such attempts usually don't succeed, while also curtailing my freedom in the process. And just to reiterate, this doesn't apply if there are negative externalities that affect others.