They had a similar ruling in the NFL, and honestly it has been a success in that league where the problem was even more glaring (given that Blacks made up the majority of the workforce). They've gone from having almost none to a fair amount. It is hard to say how prevalent racism is at board level, but the fact remains that there are not enough Blacks being represented at managerial level given their presence on the pitch and in other aspects. I don't which side is at fault, or how to address it really, but it is something you notice.
Also, I think there is some bias about the "image" of a manager. Pardew looks like a manager. Maybe John Barnes and Paul Ince do not.
A decade ago in the NFL it was ridiculous, they've come a long way.
YNWA