I would really rather not homogenize everything to the point where it looks far more like the NFL or NBA than the college football of five years ago, much less 25 years ago. Although unfortunately with recent moves that seems to be the direction we're headed.
College football is built on crowning a season champion. Most other leagues are built on crowing a postseason champion. These are two different approaches that can of course both be fun. But the difference is what makes CFB stand out among most other sports. When someone hoists the crystal ball in early January, it's the result of a truly special season. Every game was vitally important, including games way back in early September.
In sports like the NFL, NBA and CBB, the season is a qualifying run for the postseason. Regular season games only matter in so far as they help you get in and get a high seed in the playoffs. Winning the playoffs is the real goal. Many people have become convinced that this system determines a champion in the fairest way. I say this is not the case at all. Brackets are great fun to look at, but ultimately they aren't that great at determining who the best team was in any given year, especially in single elimination versions. The team that has all the important elements come together at just the right time (health, team chemistry, momentum, luck) is crowned champion. This has historically included plenty of teams that had quite unimpressive seasons on the whole (1995 Rockets, 2011 Giants, 2010 Packers, 2003 Marlins, etc.). Everyone loves a Cinderella run, and I wouldn't for a second deny the excitement in watching these teams beat the odds and make improbable runs to win the playoffs. But let's not confuse that with being the best or most deserving team in regards to the whole season.
In CFB, the bowl system has attempted to take the two best teams (often both undefeated) that normally did not get the chance to play each other, and let the championship game act as a tie-breaker of sorts to crown the season champion. Therefore the only teams involved are teams that had truly championship-worthy seasons (99% of the time, no more than one loss). This has sometimes resulted in controversy when the #3 team, and sometimes even the #4 team, seem to have had championship-worthy seasons as well. And for this reason, I am not disappointed with the four-team playoff (although I am disappointed in the selection process).
But historically I think you will find it very rare to find #5 or #6 teams that had truly championship-worthy seasons. That's not to say they didn't have great seasons, but for one reason or another they clearly fell below the level of greatness that CFB national champions have almost always had. And for that reason, to start to expand beyond four teams is to move college football away from its unique history and allow for the possibility of more and more national champions whose whole-season effort came short of the traditional championship-worthy benchmark. And it's also to move college football into a more postseason-heavy value system, stripping it little by little of its unique season-centric value system. The more teams you expand the playoff to, the more games like this year's Auburn-Alabama (or, closer to home, 1971 Nebraska-Oklahoma) lose their ultimate importance, and become mere seeding struggles. I love the fact that these games are absolutely legendary and held importance to the championship in ways that no regular season match-up between the Heat and Pacers, Broncos and Chiefs or Buckeyes and Badgers (basketball) ever could.
Although I get just as googly-eyed staring at a enormous 68-team March Madness bracket, I find the college football way to be more unique, more exciting on the whole, and ultimately more fair. I know my arguments won't sway anyone, as most people long ago determined the BCS was the devil and playoffs were the fair way to "settle it on the field". But I figure I would lay out what I think at least.