Very simple: Minnesota hasn't been punched in the face yet.
MSU losing to Washington is not proof that they are a bad team just like Wisconsin losing to Washington State does not prove they are a bad team. Those two Big Ten teams cruised against poor competition, just like Minnesota, but didn't handle the first time they were punched in the face very well. MSU got down big against Washington (who looked like a very good team to me) in the first half but stayed tough and outscored Washington 20-10 in the second half.
I haven't made a prediction in this game but this game worries me and I don't understand why any Gopher fan would be unconcerned. Michigan State still has plenty of talent on their team and has more riding on this game, especially at home, than the Gophers.