To maintain premier status in college sports, a program must consistently contend for and, at least occasionally, win championships. Michigan State has done neither for the better part of the last 20 years.
The Heisman Trophy is the NCAA's most prestigious award given to the most outstanding college football player. See the Spartan and Wolverines who have won—or gotten close.
There are more important things to be upset about than Kenneth Walker III not winning the Heisman. He will be a millionaire if everything works out for him in the NFL.