Why Elon Musk is really building Starlink

Simple solution. In the early 1990s electrical generation was becoming a big deal. And many companies started to build power plants to sell electric to mostly the wealthy and close by local residents and factories at a very high profit. In fact only the wealthy at the time could even consider electric in their homes. However there was little profit in building infrastructure to those living in rural areas. And since it was unregulated they charged what ever they felt like. However in 1920 a law was passed called the  Federal Power Act. It forced power companies to charge the same price to all users. And also forced then to build infrastructure and power lines to that farm 10 miles out that they would not normally not do.
So we all have affordable electricity now. That's way more expensive to implement and maintain than internet
But ever wonder why your power bill doesn't fluctuate daily or monthly like auto gas does or internet service providers do? It's because the federal government regulates their profits. If I recall say FPL here in Florida can make a very fair 20% profit after all expenses. Electricity is not only affordable but  our most treasured utility and including water that's also regulated. And it's amazingly affordable to everyone because it's regulated by the government.
Yet ISPs like Comcast, or others can do whatever they want.
So they are not going to pay to run expensive fiber lines to rural areas. Of course not because they simply don't have to. It's unregulated. Why because it's not in the interest of their shareholders that want big profits. This same thing is true of the big pharmas. Why are fiber lines run across vast oceans? Because it's profitable. Yet why can't ISPs run Internet cable to rural house's in the US when electrical lines and poles are already in place? Not rocket science it called Greed.