If that's the argument, let's talk about West Virginia. They won three BCS Bowl games before joining the Power 5. They beat Georgia, destroyed Oklahoma and destroyed Clemson. Who did they beat before taking on those name programs? Nobody. Who did Boise State play before beating OU in the Fiesta Bowl?
If you win 25 games in a row, in D1, you deserve a shot in the playoff. And while we're at it, teams that don't win their conference shouldn't be allowed in the playoff. The conference title should serve as an eliminator. If you don't win that playoff, you don't deserve a shot in the national playoff.