ns,
I agree that switches and other Electrical devices do not belong where they can be reached from the shower or tub. I make every effort to keep them as far away as I can.
But ... according to the NEC as long as the switch is not located within the limits of the shower stall - there is no distance-from requirement. There is not even a GFCI protection rule for this switch. If it was a Hot Tub, Spa or pool it would be very different though (- it must not be closer than 5 feet).