Stanford and Cal make some sense for the ACC. Its goal should be to prepare for FSU & Co.’s eventual exit, no later than 2036. When that happens, you want to be big enough to be able to survive and fend off the Big 12. And who knows, if the ACC loses FSU and Miami but can hold onto its middle tier, it might be able to even poach the Big 12 - UCF would be an obvious target in that case.
And those schools are snobby enough to be enthralled with playing Duke, UNC, UVA even if means flying across the country for all of their games. They see themselves as better than the Big 12.
I don’t think this is necessarily a stupid idea given the situations all of these actors find themselves in.