If we take the way back machine to the origins of the college bowl game, we find that it was a gimmick to draw people to Pasadena and generate more interest in the Rose Parade. It was akin to hat day at a baseball game. The only reason good teams were chosen is that an 11-0 Michigan team would draw better than an 0-11 team. The "reward" was really saying "you have played well enough to generate enough fan interest that we think you will fill seats at the game and make us money". In other words, even if you played the toughest season of any team in the nation and went undefeated, if there was no buzz about you, you were worse than a team with a couple of losses but more fan interest. To show you how little people cared about "a reward for a good season", because of Michigan's 49-0 drubbing of Stanford in 1902, the next year they switched to chariot racing replacing one gimmick for another. That lasted for more than a decade before they decided to return to the gimmick of football. During the 1930's, the "tradition" was to use exhibition games for things like charities.
The only "tradition" about the bowls is that they were always about making money and never related to rewarding teams. That is why changing the system is so difficult because while most intelligent people have moved past the desire to watch exhibition and onto the desire to watch real competition, the individual bowl sponsers will only do it if they personally will make more money. Even if a system is put in place that makes more on average for teams and game sponsers, if some of the old bowl sponsers personally will not make any more, they have enough power to kill the idea. Because the individual bowl sponsers and conferences have so much influence into any change, the only way change is going to happen is with an outside entity forcing the NCAA to put a real tournament into place. Thus, while the idea of Congress interferring with how colleges determine a football champion seems pedantic, it is likely the only way that we'll ever get rid of the bowls and the BCS.