A massive over simplification indeed.
The problem is this: Close you eyes and think of a good football manager.
You just thought of a white man didn't you.
That's not because you're racist or sexist. It's because practically every manager you've seen through your life has been a white man.
Now imagine you're on the board of a football club and have been asked to help recruit a new manager.
You know what you're looking for: an eye for the transfer market, a keen motivator, a wily tactician, and the ability to coach your players to get the most out of their potential. And all the people you've seen fit that bill are white men. You're not racist or sexist, and neither are the other people in the same position at other football clubs, but because all you've ever seen is white male managers there is a subconscious block there which will make it harder for others to show that they have the qualities you are looking for.
The Rooney rule works because it does not confront you with the subconscious prejudices that are built up by anybody living in any kind of society. It just puts somebody who you're not used to seeing in a position to pleasantly surprise you. It's had a dramatic effect in the US, to the point where it soon won't be necessary because recruiters have seen non-white people do the job and do it well.
It will only work though if it is enforced not just for management roles, but for the coaching roles below that. That is where people learn the skills that will make them a success as managers once they finally get the opportunity. Just the opportunity to show what they can do.
