What they are in essence dictating is that gaited horses, specifically those breeds that historically have been sored successfully and whose breed associations have not taken demonstrable steps to protect the shown horse from abuse are to be brought to the show ring naked.
Note how the proposed bill does not include Icelandics? or ROcky Mountain? or Paso FIno? or Peruvian Paso? or Marchador? Mountain Pleasure Horse? etc etc
And sans the protection of a bell boot you should consider the current day dressage horse, hunter on the flat, speed racking horse etc. If a horse is in a roundy round class going on the flat and striking the fore - might that not be a horse that should not be shown in such events? Or a horse that needs a better trimed foot or rider? and a good one for the show rules to select out? Many show rules do select out such horses by requiring naked legs - I know the Roadster to Bike classes for the ASB crowd does not allow splint boots ... anyone call travesty???
And consider this - most saddleseat breeds currently are shown sans saddle pads. This could and does present a problem for the low backed horse. But some would say the process of selection in a judged breed class should select out a horse with defects which needs compensation for an undesired back.
The law in essence would select out soring.
I agree that the added teeth of banning folks from showing that violate the HPA is a step in the right direction - one the current stacked TWH show folks are fighting against.