Just because the Big Ten is an affiliation of athletics teams, that shouldn't stop them from realizing it's primarily an academic institution. People tend to forget that in these discussions.
Athletic Directors are middle-management. They don't get to tell their superiors what to do. The chancellors & presidents made their decisions with not only their athletic teams in mind, but the student body as a whole, and their communities as well. They've made that pretty clear in their letters and legal responses.
Athletics may be the most important thing to us, but it's only one piece of the puzzle they used to put together the picture here. And Warren, for all his siloing, could only inform them on the athletic side of the conversation. They considered many other things besides his input.