I think that the WD will take on a more dressage for western riders slant with higher expectations of finesse and the CD will follow the more practical western riding style for people who may never see a ranch or cattle for real but still want to get a feel for what its all about in terms of the training a horse needs
I honestly don't care what people wear (as long as they cover the vital parts for the sake of decency!!!) and I wouldnt judge anyone by how they dress for the same reason
I'm not even a western rider but if people want to do it and it makes money for the horse world I'll encourage it
A horse that can win ribbons in something will always sell for more money than one that doesnt so the more venues for that the better!!!!