Maybe not by your "Bama deserves to be in by-God" argument, but by sound, logical, reason, it does. The conference championships are the only thing close to fair in this fucked up system we call college football.
Do as you described above, and that is as fair as fair gets.
I'm going to assume that in your 6 conference champion format, they'd make new conferences? If not, here is the bullshit playoff format that you think would put the best 8 of the 120 into the post season.
1. LSU 13-0 (SEC)
2. Oklahoma State 11-1 (Big XII)
3. Oregon 11-2 (Pac 12)
4. Wisconsin 11-2 (Big 10)
5. Clemson 10-3 (ACC)
6. West Virginia 9-3 (Big East)
Leaving the at large selections out, you really think this format would put the most deserving teams into the playoff? The team ranked #23 with 3 losses makes the playoff? They deserve it? This year they are all ranked, last year UCONN would have made the post season with an 8-4 record. Having a 3 or 4 loss team making the playoffs over teams with 1 or 2 losses is better for college football?
That's a worse idea than what we have now. That might be the worst idea that I've seen.