The solutions is simple. Instead of making it subjective, make it objective. Voting people into a playoff is silly in and of itself.
There are around 120 FBS teams.
Create 8 divisions of 10 teams each. Each team plays all 9 of the other teams in their division each season. Each team can play up to 3 games outside of their division each season. Teams can reserve these games for long standing rivalries outside of their division and/or throw in a cupcake kind of game as a warm up to start the season or a mid season break. Hell, a team can play 2 cupcake games if they so choose, because these games will not factor into the divisional standings.
At the end of the season, the teams 9 game divisional record determines who the champion of the division is. The team with the best record in the division wins the championship. For tiebreakers, a scenario like the one the NFL uses for playoff seeding is used. There are no co-champions.
The 8 divisional champions play in an 8 team playoff to determine a national champion. It really is that simple. No voting. The teams play each other. If you win your division, you have the opportunity to win a national title. Every team knows at the beginning of the season what they need to accomplish. The rules are fair for everyone.
The other 40 teams are placed into 5 team subdivisions of each of the main divisions. Those teams play the other 4 teams in their subdivision, as well as 5 teams from another subdivision, and up to 3 games of their own choosing. At seasons end, each team who finishes first in their subdivision, gets to advance into the main division the next season. The team who finishes last in the main division each season, falls to the subdivision, being replaced by its respective winner.
That is how it is done. Any system you set up in which teams are "voted" in, whether it be by a committee, a bunch of writers, or some computer formulas is going to leave things open for debate. If we had last year's system, FSU would have never gotten moved from #1 and everyone knows it. The game would be #2 Bama vs. #1 FSU for the title and Oregon fans would be pissed. This way is slightly better because we will wind up with Oregon vs Bama and those are probably the teams that deserve to play. The reality is that FSU's body of work demonstrates they are really about the 15th best team in the country, but they are in because they are undefeated.
No matter how many teams you choose to take in some voting system, there will be controversy. If we went with 8 teams, who would be the 7th and 8th teams this year? Would they be 2 teams who are really deserving of the chance? If you ask me, Ole Miss is the 2nd or 3rd best team in the country, but they would not be playing even if you took 8 teams. TCU and Baylor would be in, but who would be 7 and 8? Mich St and Miss St I suppose, but wouldnt some other 2 loss team have a case to bitch if those 2 teams got in? It is all very stupid IMHO.