Thursday night football is a doomed concept. I wouldn't be surprised if the players started a rebellion and refused to play on Thursdays. Imagine the folks on Fox going crazy over this, "muh football... tell theses no good sons o b****es I pay for my entertaintment!!!"
If they arrange it right... by giving teams bye weeks prior to the Thursday night games... AND they get a better slate of games (given the money they're paying, they just may)... TNF could work. Why does the value continue to go up? Because despite it all, more Americans watch TV on Thursday and Sunday night than any other night of the week.... and its no coincidence that the NFL wants their product (which is still the most watched television program) on TV those nights.
What ESPN never saw coming was that they were overspending for one of the lowest tiers of games on the national TV schedule. After they divy out SNF, and the Sunday PM games of the week (the marquee games of the week), there really just aren't a lot of good games left.
That would suggest that Fox actually cares about Fox News content. They saw an under served demographic to exploit with Fox News, so they give them the content they want=ratings. They don't actually give a f**k about their audience. Like every major public corporation in the world, their only actual interest is money.
The NFL decides which games go to which slot. They can improve the TNF slate... especially if networks continue to up their bids. The quality of those games could be even better if they time the bye weeks right. Given the ratings disparity (TNF draws more viewers), the NFL may also feel that it doesn't have to put better games there, as they still normally win the time slot. MNF games are simply a disaster at the moment.
They watch more on Sundays because they're not commuting home from work, but broadcast television invests more heavily on Thursdays because movie theaters inflate those night's ad revenues by airing more trailers in advance of the weekend box office, which itself killed Friday and Saturday night broadcast television.