gggplaya :
They have a regional monopoly for a reason, someone had to build the network and infrastructure. Take away the monopoly, who's going to maintain that infrastructure?? Who's going to run new lines to new roads and developments??? All of which costs lots of money. Cable tv itself is very high in price, but much of that comes from tv stations wanting more money in their contracts with comcast.
This was true in the past, and is still true in some areas. Usually the monopoly was granted in exchange for a service guarantee. The city feared that if left to the market, only the affluent areas would be judged cost-effective to roll out cable, and lower income areas would never get cable. So they granted a single company a monopoly in exchange for a guarantee that all areas of the city, including lower income areas, would get service. But times have changed and even low-income areas are profitable now (how many low income people do you know who don't have internet?). In the last city I lived in, the monopoly was a straight payola scam. The city "sold" the monopoly cable service rights to the company willing to kick back the most $ back to the city per home wired.
Currently, in most areas, competing cable companies would be eager to install their own cable alongside the existing monopoly cable company under the same monopoly terms. When I was living in a Boston suburb, the city decided to allow a second cable company. The moment that decision was made, even before the second cable company had begun laying down cable, the existing cable company cut my TV+internet bill $10/mo (from $80 to $70 - so more than 10%).
What you say is still true for disperse suburban and rural areas. They're generally not cost-effective to wire up unless they're subsidized by denser suburban and urban areas. But you have to judge whether the harm being done to the vast majority of people living in urban and suburban areas by these cable monopolies is worth guaranteeing people in rural areas have cable TV/internet service. As technology improves, more and more rural areas become cost-effective to wire up, and the monopolies become more and more detrimental to society.
I actually think we're beyond the point where cable TV+internet should just be turned into a utility. Having lots of different cable companies made sense when the industry was first starting up. Nobody knew the best way to wire up homes, the best way to distribute signals, and (for Internet) the best way to allow upstream signals. The free market is a great way to solve nebulous problems like that, and you needed the different cable companies which were willing to try different ideas to figure out what worked best.
But at this point, most cable TV distribution schemes are standardized. Most of them use the same DOCSIS modems for Internet. And I think it's clear to everyone that the endgame is fiber to the home. Just make it a utility and run it like gas or electricity. One company gets a contract to lay down and maintain the pipes, but they're prohibited from selling what's carried by the pipes. Instead, the homeowner is allowed to pick who provides the service from multiple competing companies (like you can pick from multiple long distance, gas, and in some places electric companies).