Of course it's a money grab. But unlike the B10 and P12 presidents, the SEC presidents aren't sitting behind hypocrisy. They know that if they can justify admitting tens and thousands of students on campus in close corridors, they sure as hell can allow 100 some young men who are closely monitored and tested frequently to play football. Not sure how you don't see this?
I don't think that's quite apples to apples. The Big Ten/Purdue is not banning the football team from doing any activities. They have practiced, worked out, etc. - that's the equivalent of having kids on campus.
The issue has a lot to do with travel and testing/contact tracing. For example, Purdue is not allowing students to have visitors outside of the "Purdue bubble", nor are University departments. What these schools want to do is minimize the exposure outside of that respective "bubble" (sorry for lack of a better word) - and travel makes that more challenging and also to trace it back.
The testing is another challenge that the conferences playing also have - the testing is not instant. These teams are getting results of tests 2-3 days later last time I saw. So if you're getting results in 48 hours, a test Wednesday morning would come back before a team travels on Friday. And a test administered after a game day would not be available until late Monday/Tuesday - meaning a full day of classes, time with teammates, roommates, etc.
I think the testing is the biggest hurdle. As the Pac 12 said about their agreement with rapid tests later in the fall, it's a game changer as they are cheap and don't have to be shipped off to a lab. You can test everyone before practice, a workout, game, etc. and know before that starts whether they should be sidelined or not.
Overall, I think the "nightmare" scenario for all of these conferences that have postponed fall sports is based on a team traveling, a player coming back to the "campus bubble" and spreading it in their dorms, to teammates, in classes, etc. And it starts an outbreak. Because in theory, the team (gathering of 200+ people for a football game day in different states) would be going against all of these policies the university has in place. It certainly may not happen, but it certainly could. You can come up with theories on every conference - the ACC, for example, is terrified of Clemson/FSU leaving to the SEC so it will probably do everything in its power to keep those schools happy (same with Big 12 and Oklahoma/Texas).
Whatever the Big Ten does I just want to see them have a plan in place that can be executed (i.e. 2 games involving Big 12 teams have already been postponed). If there needs to be time to feel comfortable in eliminating some bumps, so be it. But what's not going to be fun is games being postponed, there being a completely unbalanced schedule, there isn't enough preparation, teams have entire position units depleted, etc. - that's not fun for anyone. If there are things like rapid tests, campuses seem to have the initial student arrival surge under control, etc. -- then let's start as soon as it is feasible.