In a series of one-and-done games, the results can be so flukey I just don't see much reasoning behind putting any weight in the results.
The ACC teams that got knocked:
Virginia Tech - sizeable underdogs
Virginia - slight underdogs
Duke - an actual upset, but we're talking about the #7 team in the country losing to the #26 team in the country. This happens all the time.
Notre Dame - underdogs
Florida State - this was pretty bad
Miami - slight favorites
Louisville - lost to the #27 team.
Saying a conference is over/underrated based off one game from each team is silly. If Syracuse were judged off of one bad game (St. John's), people would think we were the worst team in the country. If they judged Syracuse off one good game (Florida State), they'd think we were one of the best in the country; it's no different when you do the same based on the tournament/bowl outcomes.