McDowell can't be blamed for guys like Medlen, Beachy, Hanson, etc. They had terrible mechanics before getting to the bigs. By the time they get here what motivation do they have to change what made them successful?
I'm not really blaming McDowell for that. I just find it funny that the hated Leo had great pitcher performance without having many pitchers blow up and when he's gone we now lead the world in Tommy Johns. Personally I think it's a curse by the baseball gods.