If the rule was meant to rectify "cronyism" why not make it so you have to interview at least X amount of coordinators and not specifically minority personnel? If I remember correctly, when the rule came into effect there was an out cry from players about the disparity in the percentage of black players and black head coaches.
In the end I think it was a good rule, only because we do not see the same old coaches with different teams every year. If anything the pendulum has swung the other way whereas every team wants to hire the youngest and freshest coordinator they can find. Even if they are one hit wonders (like Mangini).