I don't know why this is news. Everyone knows Michigan and Michigan State don't care about each other. Michigan State's rivals: 

1 - Notre Dame. 
2 - Wisconsin. 
3 - Ohio State. 
4 - Michigan. 

Not a slight on Michigan, but -- other than a couple decent years in the 90s -- they haven't been nationally relevant since Hitler was running the show in Germany. Further, games against Notre Dame, Wisconsin, and Ohio State have been far more entertaining, and the fans that comprise those fan-bases are enjoyable and fun to talk sports with. Michigan's just sort of... there... They're not really important, but they are the other premier institution in the state of Michigan so you have to take that for what it's worth.