The rankings have had an anti-SEC bias for some time. I've been on both sides of this debate in the last couple years, admitting that the SEC is not that strong, even weak sometimes, but also defending it against other supposedly superior conferences. Iowa State is ranked 16th? Are you kidding me? You take their record and put an SEC team's name on it, and it wouldn't sniff the Top 25.
That's how it and the B-10 get so many teams in the dance. They go through this supposed gauntlet in their super tough conferences, facing so many ranked teams, but it's all a sham. Just because a team is ranked doesn't mean they are any better than some teams that are not ranked, who happened to be in conferences like the SEC. BTW, ISU is 25th in the BPI, and Georgia is 26th. But Georgia gets 0 votes in the AP ranking. But, nah, no bias.