Given the rule changes to no spinning within a week of racing it cant surely be the issue. it it scientifically proven to be performance enhancing??I have not seen any evidence to say so
So how can it be a bone of contention when its openly available to all stables. Also, i think you'll find its not the stables that have the spinning machines as you put it, that's all done in separate lab with resultant serum reintroduced by Vets as per new regs.
If you remember a horse called Carabella, it was treated with spinning so that shows how long its been around