Actually, privatized toll roads are the coming thing these days! Some states have sold off roads; others have allowed private companies to build from scratch. The road to Dulles Airport near Washington is a prime example.
But the comparisons to WiFi here don't really work. No one charged extra for electric light in hotels when it was new; it simply replaced the gas lighting. It took 70 years of broadcasting to create a pay system.
As for WiFi, or internet access in hotels generally, it's not that new. It's a mature technology, the costs are known, the R&D is paid off, and—key point—the high prices charged by some hotels to use it profit the hotel, not the developers or the providers of the technology. It's more comparable to $20 charges for reprinting a boarding pass.