It is a little unfair to just look at this year and say that there is some sort of issue with the amount of minority coaches in the nfl. The current number does not reflect the unfair hiring practices of the NFL teams but lack of production of 4-5 black head coaches the past couple of years. I think there were about 25% of minority head coaches in the NFL last year but several black coaches were fired for valid reasons. I think this year is just a bump in the road for minority coaching. I see more and more black coaches coming through the ranks and it is only a matter of time before some of them are deemed ready to be the head coach. I don't think this has anything minority coaches being overlooked.
Never be satisfied with what you achieve, because it all pales in comparison with what you are capable of doing in the future.