I know college football season is over, but i still don't know why...?

It's all about money. The other bowl games before the BCS can earn more in ad revenue because they are the only games on TV. This process maximizes NCAA revenues. It's a shame that we can never see teams go at head to head in the championship game while they are still in the flow of the season. Three weeks off has to mess with teams that are hot ending the season.