It's true that we played a great game against Mich State. But you also have to remember that they probably didn't want to be there any more than we wanted to be in New Orleans after the 2008 SECCG.
They were tied for the best record in the Big 10, but couldn't go to the Rose Bowl because of tiebreaker rules. The specifics are fuzzy for me, but I seem to recall that it was something other than a head-to-head loss to one of the other teams. Or maybe it was a three-way tie and each of the three had beaten two of the others, but lost to the third.
Whatever the details, MSU felt they were the best team, and were denied the Rose Bowl by some bureaucrats.
So they saw a 3-loss Alabama team, underestimated us, and didn't want to be in Orlando in the first place. We were healthy for the first time all year, and were out to show the world that we were still Alabama. All that combined for an embarrassment for the Spartans.
Not an exact parallel with our own experience with Utah, but close enough to be indicative.