It's not a coincidence that Michigan's defense sucked over Rich Rodrigez's three years. And despite having only about 70 scholarship players in 2009, Robinson actually had more defensive players in 2010 and things still got worse...
...but the move to the 3-3-5 was stupid for Michigan's personnel and strengths.
I'm not convinced that Robinson is a horrible, horrible coach, although he's obviously not a great one.
I am convinced, however, that Rodriguez's defensive hires and decisions were bottom of the barrel.