Imagine if your utilities were not regulated, allowing, for example, your electric company to provide shitty, spotty service. And this is at sky high prices. But you have to pay because you need electricity.
Even worse, now imagine your electricity company decided to make AC, TVs, and refrigerators. Imagine if they cut power to any AC, TV, or refrigerator that was not of their brand. You're a captive audience now, you think their brand of TV (or whatever) is going to be quality?
Alternatively, they don't go into the appliance industry. They extort GE: if you don't pay us we'll intermittently turn off power to GE fridges and your customers will blame it on poor manufacturing. GE has no choice but to pay... and now you pay more for GE fridges.