If there is a game on the team's schedule, the players, coaches, and fans want to win it. The regular season would still matter for seeding purposes and for teams who are trying to win their leagues.
If I had my way, there would be no more than 6 divisions for 11-man football, 1 division for 8-man football, and only 4 teams per region would be qualifying. The expansion to 8 teams per region reduced the incentive for many playoff caliber teams to take risks with their schedules. As a supporter of a smaller school, the addition of a 7th division felt like it greatly diluted the competition among what is now DV-DVII. If adding that 7th division wasn't jumping the shark, then expanding to 12 teams per region next year is jumping the shark and a whole lot more. That'll be 336 teams making the playoffs which represents more than 45% of teams that play 11-man football. As I stated earlier, I'd rather see the playoff system be contracted, but that's never going to happen. With that being the case, quit delaying the inevitable and rip off the Band-Aid. Let everyone in, and add 1 more week to the playoffs.
I admit that the biggest obstacle would be the likelihood of a shorter regular season which prevents many schools from having at least 5 home games, and I fully realize how much athletic departments rely on either having at least 5 home games or having a way to generate revenue equivalent to having 5 home games.