Much of the hate is because Mike Rumph is not perceived as a 'savage'. Miami hired one of the best DL coaches in college football and fans wanted a DB coach of similar reputation. Rumph does not have a resume comparable to Kuligowski. At least he has a deep connection to success at Miami and was a very successful at Heritage.
Did he bad-mouth Miami while coaching at Heritage? Can you blame him for advising young men who played for him there are better options than playing for the disaster known as Al Golden? Would you have recommended Golden's Miami to players? Be honest.
Then again some guys have never seen snow or frost...