The BCS system is a complete joke. Year after year a valid team gets snubbed because an undeserving team from one of the major conferences gets in and inevitably gets destroyed when another team could have done much better. A playoff system has no downsides, and will promote much more competitiveness than the BCS.
When we end every other season wondering if any of three to five teams should have been champion, there's a problem. Simply naming the top two teams in a national championship game works exactly nowhere else because everyone else, from middle school tournaments to the highest level of international competition realize a strong team getting hot deserves a chance to win the title fairly.
As a football fan, I would say yes, a playoff system would be a far superior way to determine the true champions of college football. It is difficult to respect the legitimacy of any system which relies so heavily on arbitrary rankings. However, the other side of this is that a playoff system would require many more weeks of football to be played, and we already have enough trouble with the demands of college athletics on the student athletes diminishing their ability to earn an actual education. Most of those young men will never see an NFL field except from the stands as it is.
What is the big deal with what is happening now? It seems to be working fine as it is--players are playing, games are won and lost, and people are enjoying the competition. Is there some reason that things should be changed that I don't know about? Unless it's a really big issue, I see no reason for change.