Has anyone mentioned that the Irish played, all in one season, the 2nd, 3rd, and 4th best teams in the country?
Yes, there is an argument to be made that other teams were better than Ohio State and/or Stanford; but there is also a strong argument that those two were better than any other team not named Alabama or Clemson.
What's more, no other team in America can say that they were tested to that degree. Even Alabama, playing in the SEC and championship tournament, really only played the 2nd best in team in America and maybe one other top ten team. It was a pretty good Michigan State team: good enough to catch Ohio State napping but, based on the Spartan's performances against Alabama and Iowa, not nearly as good as either Clemson or Stanford. And after Michigan State, the quality of the Tide's competition falls off precipitously with no one else in the top ten.
Granted, Notre Dame went 0-3, and if you want to argue that a miss is as good as a mile, then maybe you think there is no merit in pitting yourself against the best. Me, I like to think playing competitive football against the very best in all of college football will pay dividends down the road.
Iowa was a better team than Notre Dame this year because, what, they beat up on the Illinois State Redbirds, the North Texas Mean Green, and the Iowa State Cyclones? Or was it because they beat Pittsburgh on a 57 yard field goal? Please do not tell me that it was because they lost to Stanford by 29 points. C'mon, man.