Would you rather lose to a blueblood every year or get a possible win over a mediocre P5? You might get lucky and beat the blueblood on a down year or surprise them (see OU '05). Winning games promotes a winning perception, even if you lose to a blueblood, you still lost and if that is the only game you lose, you will have to get over that loss. It would be harder to get to the playoffs if you have to explain why you already lost to the team you're about to play.
For the fans, I think playing Bama/Clemson is a great game and gives us something to look forward to. However, I would rather play them in a bowl game than play them in out of conference play. The Bama's of the world don't care about playing a tough out of conference schedule, they want the wins to guarantee the playoffs. Play to lose and that's what you're gonna do, pave the road to win and perpetuate the attitude throughout the season. Look at how the loss to tOSU derailed that season.