Why should we join a conference?
It used to be everyone argued that we were independent for money. That is not true. Each Big Ten member gets $51M/year. Our NBC deal is reported to be worth $15M/year. Those aren't typos. Conference affiliation would be far more lucrative for Notre Dame.
They might argue that it's too easy for us to make the playoffs. Well, we just made our first. Had we lost a single game, we would not be in the playoff. Our path to the playoff is more, not less, difficult.
If they argue that we need a mythical '13th data point', just counter that we'll schedule Furman, Mercer or The Citadel if it makes them feel better.
Or they might say we take the spot of a conference champion. The only appropriate answer to that is 'so what?'.
There is no sound argument that we should be compelled to join conference. None.