The issue is profitability (similar to the post office problem) -- if your house is in a rural area with low density, it's not worth it for a private industry actor to bid on your linkage. In many parts of the US, the only ways to get mail is through USPS (FedEx & UPS just don't service unprofitable routes). However I think internet access is a human right and a public good no matter where you live or can afford to live (imagine raising children who would never have access to at least broadband-level speed -- how would they function in a 21st century economy?) - and the infrastructure can only be provided equitably if the government steps in and subsidizes away the profitability problem.