Pre-season rankings artificially bolster--and punish--teams before the season even starts. Teams schedule their way to wins. Conferences vary dramatically in terms of quality. Some teams (like Northwestern this year) get super lucky with their conference schedules.

I don't disagree with your larger point, but there's too much variability in college football for me to buy in to your comparison to March Madness. At least the NCAA basketball tournament directors try to create "fair & balanced" brackets.