Not to derail the thread, so I will just do the one reply.
I think you are forgetting the genesis of the Rooney Rule and how long it's been around. It was implemented in 2003. At the time it implemented, there had only ever been a total of 6 minority HC's in the NFL. In it's entire history.
It's pretty dumb to think that the Rooney rule has had no effect in giving minorities a chance that they otherwise probably would not have gotten over the past 20+ years.
Although, I do think the even bigger effect now is how they have carried it down to the coordinator level - especially at OC.
IMO, it gives people a chance that they probably would otherwise not receive to learn the process, learn what owners and GM's are really looking for, and hopefully get feedback to make themselves better. At least that's how I think of it.
en.wikipedia.org