My understanding (though I don't have any sources and it could just as easily be hearsay) is that nicer hotels jumped onto the new business model and signed long-lasting contracts with providers of internet service when things were just getting established. So it's less that nicer hotels are necessarily trying to milk you, and more that the nicer hotels jumped onto the bandwagon when it was still a bad financial decision, and are passing their bad luck onto you.

Of course, I wouldn't at all be surprised if your suggestion is right, and they're just trying to milk the more well off clients.