It isn't protectionism, the problem is that it either the return on investment isn't there at all (wiring a sparsely populated area never will be) or the return on investment is better in other locations.
This is a free market failure that doesn't provide residents of these areas any options for decent broadband. They can either wait for years and hope the ROI equation changes, or they can try to bring in an alternative that doesn't have to concern itself with meeting an ROI target (i.e. municipal broadband, or start their own COOP)
The city owns fiber in only a handful of places in the US, but almost everywhere the city owns the right of way where cable company & telco fiber is run. Owning the fiber is not all that different than owning the right of way - owning fiber and leasing access to all comers may be the best way to inspire free market competition as the barriers to entry are far lower when you don't need many millions in capital to run your own fiber before you're eligible to compete.
Today's situation where companies own/run their own fiber means that in most areas you have only two choices for wired broadband so it is hardly a situation rife with "competition and improvement". An oligopoly does little to drive down prices, and that's one of the main reasons why US broadband prices are some of the highest in the developed world (even after adjusting for cost of living)