As a fan of a team (Marshall) that made the transition from I-AA to I-A (the new names of FBS and FCS are dumb), let me explain how it worked with playoffs.
MU was in the Southern Conf., which was the SEC of I-AA in that era. The regular season was thus, pretty much, degraded. All you had to do was go 8-3 or even 7-4 and you were in. There never was a "big showdown" in the regular season at that level.
Also, at that level, and this will I grant you might be somewhat different in SOME I-A conferences, people knew that we were going to play 10 home games. Ten games is a lot, and many people just could not afford season tickets plus 3 playoff games plus the championship game (which we hosted). They had to pick and choose.
Then came the playoffs. First week was Thanksgiving, and it was against an automatic qualifier we knew we would wax by 30. Students were gone, people had other plans. Stadium was half full, if that.
In the next two rounds, at least one week was played (and this is Huntington, WV, forget about discussion of Boston, State College, Minneapolis, Madison, etc) in a snow storm.
Being work-a-day weekend before Christmas, the visiting teams brought, well, parents and girlfriends. You just cannot play gypsy across the country on 6 days notice every weekend. One year we were, unfairly, sent to an away game in the semi-finals. In Montana. We took a few dozen. It just cannot be done otherwise on that amount of notice.
The Championship was sold out. When we played in it (which was three out of the four years we hosted it). The fourth year, there were maybe 6000. The year prior to our hosting, it was in Charleston, SC. We played in that, and again, about 6K were there.
It degraded the regular season, it was not college football as I love it, and the day we moved up to I-A and got in the wonderful bowl system, was a great day.
If you like playoffs, watch the NFL and leave to most perfect regular season in the world alone.
And, BTW, congrats to Villanova.