Telephone and electricity wires cost money to run as well. We mandated that the utilities provide service to all and they used to simply spread the cost over the entire customer base. As long as you're profitable in the large it doesn't really matter if each customer turns a profit. However, if a company is not required to do so, they will, of course, focus only on profitable customers.
We chose to subsidize services that were viewed as vital, such as phone and electricity. Cable TV is not a necessity but internet access may be.