Notre Dame has a great schedule resume this year. Some of their opponents fell off a bit but they could have two conference champions on their schedule if the chips fall right this week for OU and Stanford...two quality power conference champions to boot (2nd and 3rd only to the SEC). Regardless, they beat a top 3-ish team in the Pac-12, Big-12, and Big Ten in one year.
Think of it this way: they had 4 gimme games scheduled - just like most teams in a conference - and they were all quality independents or lower-tier ACC teams (Navy, BYU, Wake Forest, and Boston College). Pitt, Michigan State, and Miami fell short of expectations but that slate is about the same as us playing Tennessee, Ole Miss, Arkansas, and Mizzou in-conference.
Their schedule top to bottom is stronger than our schedule or any team other than Florida in the SEC because they didn't schedule a single mid-major. Navy is consistently the toughest Service Academy - they've beaten ND a bit over the last few years - and BYU is a team that won a national title and competed at the top level well recently too. Wake and BC are bad but they're a tougher out than scheduling FAU or WCU just by pure talent on the field.