Dead nuts spot on.
More than money today, schools want a stable home right now that has long term staying power & relevancy. The ACC has zero stability. They themselves are a giant hodge podge, couple state flagships hoops schools here, couple of southern football schools, a Boston Catholic, a city commuter school, two Bay Area schools, SMU/Wake. I'd argue that the B12 has more conformity in school type than the ACC. The ACC is as good as dead if the Big4 leave. No one cares about short term money ahead of having a long term home.
If Stanford/Cal don't find a way into the B10 to pod up with the other 4 Pac12 leavers, then my hunch is that they'd just trying to figure something out in the new Pac once it firms up. For two olympic sports heavy schools, the travel to the ACC or anywhere eastward long term isn't sustainable on any level.