That's just an overly broad generalization.
Notre Dame's ability to SCHEDULE teams has been based on various conferences having an 8-game schedule, as well as the ACC's desperation to have "partial Notre Dame".
Once the Big 10 and SEC expand, and the leftovers form a third overly-large conference, and these conferences begin to schedule 10 conference games per year, it SEVERELY limits ND's scheduling opportunities.
And when the networks have a chance to bid on 20 team super-conferences for their football content, compared to a measly 7 or 8 games per year of Notre Dame vs. The Service Academies and Other Religious Institutions, then ND is simply NOT going to be able to remain independent.
"They don't have to for football". Hilarious.