simple fundamental shooting just isn't "kool" enough to some people. They simply must add a dozen ninja maneuvers so that they feel like they are doing something. in addition to that, there are trainers who have the idea that every student must walk away with the feeling that they have learned something more than they knew before - so they incorporate their own specific kabooki dance or maneuver so that you don't feel like your money is wasted. There are only so many ways to perform in a gunfight and all this over manipulations can be a bad thing.
Life is a web woven by necessity and chance...