I never said 9 at large isn't fair. The 12 team playoff with 5 top conference champs and 7 at large is already fair enough.
The main point is that the expansion of playoffs at this point is about greed and not designing a better method for crowning the best team in CFB. Arguably, the best system for crowning a champ in CFB would be a 4 to 8 team playoff. Anything beyond 8 starts to undervalue the regular season. 12 is more than ample.
Looking at this past year's rankings, the last two in for a 12 team playoff would be Ole Miss and Oklahoma. For a 14 team playoff (if 9 at large, though I think it will just be more AQs for the top conferences), it would also include LSU and Arizona, both three-loss teams. Just seems excessive at that point...