... will ruin the importance and excitement of the regular season games

The NFL has a very inclusive playoff system, and its regular season games get much higher television ratings than college games.

The NFL's ratings advantage over college football has nothing to do with its playoff format.   College football gets lower ratings because most of its top teams are located in small TV markets like Austin, South Bend, and Columbus.  From the beginning, the NFL owners set up their league as a profit-producing enterprise and placed their teams in the largest cities, like New York and Chicago.

Bleacher Report - College Football