Because they need home games for ticket revenue. They are also trying to buy wins, but things will be different with no crowds and no home court advantage. If there are OOC games I would assume the football conferences would just play a few games against each other.
1) In regards to ticket revenue, I think you'd agree that UNC or Duke could either sell more tickets or more expensive tickets for Kentucky or Florida than they can for Longwood. So then it comes down to whether 1 home game against Kentucky is worth more than 2 home games against Longwood, including the buyouts. I'm not sure if that holds up, or at least to the extent where it makes a significant financial difference, which brings us to 2), which I think is the real reason why we have buy games.
2) If there's an NCAA tournament, which I think conferences have to assume while planning for the season, it would still behoove them to play some easier opponents in order to increase their conference's NET. If P5's skip OOC or only play each other, a conference like the A10 could leapfrog them if the A10 goes out and dismantles other mid and low majors because our conference would be filled with 'tougher' opponents. Further, elite P5 schools could probably host bubbles at their home arena, which would still provide some home court advantage even if the arenas are empty or partially full.
I think it has more to do with the P5 conferences aligning to figure out non-conference bubble scenarios. It is not necessarily about not wanting to associate themselves with the likes of Longwood.
Not sure I follow. They want to align so they have the same safety protocols, have equal culpability if something goes awry, or something else?