Well, I've said on this board for years that the ACC was quietly making better coaching hires. The problem is while the ACC is vastly improved as a whole, it's not as predictable where the improvement is from year to year. Virginia made a good hire and should be better. NC's culture won't let them really improve. It's the usual suspects, FSU, Clemson, and maybe soon, Miami--the teams who have at least some history of winning big--who have been able to step up. In general, your division of the ACC has maybe the best lineup of head coaches in the NCAA.
As for the SEC, the hype peaked the year all those SECW teams tanked in their bowls, including the MSU team you beat. And that seems to be right when things particularly went south. My latest theory is Saban has raised the pressure level to the point that coaches are fired whether or not there's a good replacement. And in this sport, there just aren't many great coaches. LSU, of all programs, ends up with Orgeron, South Carolina with their fourth choice, Muschamp. Others take the Auburn route--fire all the coordinators and assistants (Notre Dame also did this) which is the WORST way to improve a program. Impatience to catch Saban has placed everybody farther away from Saban.