Am I missing something here? I'm genuinely curious why anyone would think it's a good idea to surrender control over something that directly affects their everyday comfort, especially if it's air conditioning in Texas.
It partially compensates by cooling the house down before peak. Also, you can override it at any time and it will learn what you want. The point is to find ways to cut back that don't affect comfort.
It's a good idea if the money you're paid outweighs the discomfort you feel.
This is an attempt to find a consensual market solution to the problem of building expensive peaker plants that operate perhaps a day a year. The marginal cost of electricity generation capacity is astoundingly high.
Part of Nest's angle is that Nest can learn and detect whether you are home. This lets the thermostat save you money when you're not home - and this is the key - it does so without any thought or input or effort by the customer.