There are rivals I will pull for, and rivals I won't.The ACC, due to a much smaller overall alumni base, will never rival the following of schools in the other power 5. That said the footprint for recruiting has its advantages and unless a school completely abandons even trying they will be players in whatever lies ahead.
Clemson fans have never been "conference fans", I've never pulled for unc or duke in hoops nor fsu in football. SEC fans through talk radio and message boards have made it so folks route for historical rivals. Nuts.
I want my team's conference to look good, because that generally helps make my team look better. But there are some times I just can't do it, and some teams I can NEVER cheer for even if it would benefit Iowa State.