Proactively than the B12 (think Louisville), have better conference leadership, have a more iron-clad GoR, better television/media including the ACC network, a much stronger and more populated footprint, stronget academics, and more FB, hoops, and other sports success of late compared to the B12.
FSU and Clemson already said no thanks to B12 feelers a few years back. Being at 14 temas + ND is a whole lot more stable than the B12.