It can only be explained if you completely throw out the committee's seeding that was released. We were at 4, Illinois at 8 and Michigan State at 14.
Since that day:
ISU lost @ BYU (ranked), Texas Tech (ranked) and @ Arizona (ranked) and won two games against Utah and ASU.
Illinois lost @UCLA, @ Michigan and beat Oregon and Maryland
Michigan State lost @ Michigan and beat OSU, @Purdue, @ Indiana and Rutgers
Basically, Illinois has done nothing impressive at all to gain 4 spots on us and Michigan State has one impressive win (@Purdue) with admittedly two games better record but that's supposed to jump them 10 spots?
Personally, I think the strength of the Big 12 is enough that this conference deserves a 1 seed (Arizona) and two 2 seeds (Houston, ISU) and two 3 seeds (, KU, Texas Tech) while the Big Ten deserves one 1 seed (Michigan), one 2 seed (Illinois) and three 3 seeds (Michigan State, Nebraska and Purdue).
I think that's a very fair distribution based on relative conference strength since we didn't have the benefit of playing against the bottom of the Big Ten, which has 5 teams with losing records (the Big 12 only has 2).