How many minorities are involved in hockey anyway? I can't speak for the demographics in the U.S., but in Canada, outside of a handful of small pockets in Toronto, Montreal, and Vancouver where East Asians, Arabs, and Africans usually emigrate to, hockey is pretty much exclusively the domain of white Anglophones and Francophones. First Nations, Metis, and Inuit are other groups that have even less representation.
Given the fact that few minorities actually play hockey in Canada, you don't need to be a genius to see why there aren't many minorities involved in high level coaching. You can't expect an apple tree to give you fruit if you planted the seeds yesterday. The fact is that minorities historically haven't been interested in playing hockey in Canada as most parents had their kids playing the sports of the country they came from. This is why there aren't qualified minority coaches in the NHL. They simply don't exist.
Aside from Ted Nolan, who would you say deserves to be there? You probably can't even name one (and whether or not Ted Nolan deserves to be a coach in the NHL is debatable).
Like I said, this idea is moronic. If a coach knows the game and is good with players he'll be there. His skin colour won't matter.