I think socioeconomics play a big part; in the boys/mens game, lads can easily find a game locally, there are scouts for professional teams scouring local parks of a weekend, loads of FA registered sunday league clubs playing, far, far more opportunities. With girls/women's football, it's harder to find local teams for a lot of girls, less clubs, so more travelling, perhaps higher entry costs etc. Far fewer scouts out there looking for female talent (women's football is far less lucrative right now). So the higher entry cost perhaps has a bearing on the diversity within the game; maybe the white girls are coming from more privileged families who can afford to support them more. Very highly complex, but a very interesting subject.