I’m sure not everyone, ND fans included, would agree but that’s OK
How many "conference" teams have to travel to NYC for one of their "home" games? How many conference teams have to fly to San Diego one week, travel to Chicago the next week, have the one real home game of their last five, fly to New York the next week, then fly to Los Angeles the final week? How many play two B1G teams, two PAC 12 teams, one SEC team, 5 ACC teams, and NO FCS teams?
ND has defeated 3 of the current AP top 21 and it isn't their fault Florida State and USC happen to have two horrible head coaches who don't know what to do with all the talent they have recruited.
The cost to ND for joining the ACC in every sport except football (independent) and hockey (Big 10) is that they had to eliminate annual games against traditional rivals Michigan, Michigan State and Purdue in order to play 5-6 ACC games per year. They now ony can schedule those three teams intermittantly. Only Pitt and BC were tradional rivals and they can't play them every year now but can still schedule them every 3 years. Getting Clemson and Florida State on the rotation schedule is a good tradeoff.
The cost to also join ACC in football full time instead of what they have now would basically have been to eliminate USC, Stanford and probably Navy from the annual schedule (at least 2 of those 3) which they hopefully will never do. If it were not for Navy putting in NROTC students during WWII, ND may have had to close their doors so basically Navy saved ND and ND will continue to support Navy (realize many disagree with that). They will also continue to make a Thanksgiving trip to Cali every year, alternating home & home games with USC and Stanford. Wouldn’t care if they replaced Stanford with UCLA but whatever.