Actually, it is technically possible. There are in-house video distribution systems that re-broadcast feeds to other channels. I believe Lodge TV is one of these. They are used mainly with systems that offer Pay-For-View channels and Folio viewing. It may not be cheap, and given MI doesn't own or operate many of the properties, local management is going to opt for cheap when they can. Providing local channels can still be done and lining up the networks would be nice, but you also need to remember not all ABC channels carry the same ABC programming (more daytime stuff so may not be an issue). Plus, sometimes a property needs to avoid using the same channel as a very strong local station.
I look at is as part the the local "character" of the property. It's bad enough when you know what chain you are in when you see the bedding, but to have everything being "cookie-cutter" makes travel boring. It's bad enough I know how to use just about every TV remote blindfolded!
However, it would be nice if they would stop mandating FOX News in the lounges!!!