I guess I disagree that the difference was time. I think we should look at the similarity, and the similarity was a fact-blind bias against reality. MLB is seeing (and trying to play through) their fact-blind bias against reality. Football at all levels is still up in the air. I hope this doesn't result in serious health crises with players, their families, or their communities. It may not, I'm still not convinced it's inevitable, but it's a risk that shouldn't be ignored.The key difference between all the other examples and FBS football conferences (and the NFL for that matter) is the gift of time. There was time to prepare if you are a major FBS conference. The planning may have still resulted in a cancelled/postponed season, but it doesn’t appear that they used that time to truly discuss all options.
What information did FBS football not have that anyone else had in, say, early June? None, at least if they're reading reliable news sources. We all had the same information. When lots of people were handwringing about opening up in late May/early June, did FBS administrators have less information than governors? Nope, they had the same, and it was biased (the actual facts, that is) towards staying closed. That didn't happen in a lot of places. Almost certainly FBS administrators had less information at the time, but they felt compelled to rely on political leaders, who had politicized a public health crises. Nobody had good information, and everyone pretended they did. Or lied about it. Or lied to themselves about it.
So did FBS have time to prepare, or did they follow the people/institutions that they should be able to trust when making decisions in June about September?
We ALL (on a bureaucratic level, not necessarily individually) dorked it up. And now we win at COVID. Awesome.