So they are in a position to charge pretty much whatever they want for electricity. People didn't fully anticipate how a few companies would be able to unilaterally manipulate prices in a free market, and are still trying to figure out if deregulation works, or can be made to work, even. It may be inconvenient, but it's not like the lights going out. Third is that consumers don't actually know what the price of electricity is in real time. Until fairly recently, everybody know that if you wait until the evening to make long-distance phone calls, it's cheaper.
Nobody thinks that way about electricity.
When I lived in Davis, I ran our pool pump from noon to 4, because it never occurred to me to run it at any other time. But when I look at my electricity bill, there's just one rate, no matter what time of day I use power. Right now we're in a transtion period where the retail rates are frozen. Eventually, though, I think consumers are going to have real-time meters. The point is, the free-market interchange of supply and demand can only work if everybody knows what the price is, so that demand can shift in response to changes in price.