There does have to be a part of the debate that acknowledges that Scotland is a vastly white nation (90%+?), while what we are doing just now isn't enough, we have an overwhelming amount of white people and it's entirety possible that if all the managers were Scottish they could all be white.
There is work to be done but we also need to improve on the number of BAME players actually playing football, I don't have any stats on this but we must be producing a very small amount of players.