You just made a case for not expanding access to the playoff. You are using subjectivity, saying the 4th best team in the SEC is better than the MAC champ so they deserve it more. Well then both subjectively and objectively the top 2 teams in the SEC are even better, so why include 2 more?
If using subjective criteria there is no reason to expand the playoff to teams that subjectively and objectively have shown they aren't one of the real title contenders. So limit the field to only real contenders, there would rarely ever be an argument for more than 6 teams. Go to 8 to eliminate byes. And you protect the impact of the big regular season games and winning a conference means something since it might be the only way into the playoff.
If you want to expand (and we know they do solely because of money), then use predefined criteria like conference championships, division championships, conference standings, AP rankings (still subjective), etc. and open up the field to 16, 20, or whatever. But now you are knowingly expanding not for the sake of including the best teams, because you don't need a field of 16 for that. You are now objectively including teams that aren't top contenders because they either play a weak schedule in a weak conference, or weren't good enough to finish at the top of a conference that matters. So why do they need to be there? They don't. But if you're going to insist on it because you want to print more money, then you might as well give the teams that were good enough to win their conference a place because just like that 4th place SEC team, they aren't a legit title contender. At least they were good enough to beat most of their peer opponents, unlike that 4th place SEC team. But that won't bring in money so heaven's no, we can't have G5 teams involved, so f*ck 'em, right?
Every single decision is being made by money, full stop. It's ruining the sport.