To be competitive in today's market you need to be running fiber. Depending on where you're located, fiber is scarce and running it isn't cheap.
Yeah, the equipment was probably expensive, but compared to what? Laying your own infrastructure? Not even close.
This regulation was undone under the Bush administration and most of the independent DSL operators died shortly thereafter, leaving consumers with a choice between the incumbent telephone company and the incumbent cable company, in most cases, for broadband.
In short, when the market was regulated, there was competition and consumer choice. When the regulation was removed in response to industry lobbying efforts, consumer choice disappeared.
When profit margins are that high capital finds a way. What capital can't do is chop through red tape, burdensome regulation, and noncompetitive system.
Your investors aren't crazy. You challenge titans! But your difficulty isn't going to be technical. It's going to be those titans doing everything in their (significant) power to stop competition. They want to protect their 97% margin after all!
Aside from that, if you're anything like us, you will be reinvesting those profits into expanding and growing your network.
Internet access is provided by cable and phone companies. Those companies are utility companies. They have government sponsored monopolies. It was inevitable that the internet access the utility companies provide would eventually see utility-style regulation.
Net neutrality sucks. It's a shit solution. The real solution is ISP competition. If consumers were able to choose from a dozen competing ISPs then net neutrality and all this regulation wouldn't be necessary.
The true puzzle is how do we enable ISP competition. It's not easy. But it's true solution.