Actually, pumps don't atrophy and the soft food disposer does not die from lack of fiber when dishes are rinsed before going into the dw. The main thing that happens when dishes are hand rinsed to the point of almost being clean before being loaded into the dw is that unless only a small amount of detergent is used, the caustic components of the detergent have no organic matter to work on and no grease to emulsify so they go to work on the dishwasher parts. Any vinyl or rubber-like components like rack coatings, seals and gaskets have the essential oils in them pulled out by the rich detergent solution leading to the racks rusting when the vinyl covering them is damaged, leaks developing when seals and gaskets turn hard, split or get eaten away, often allowing water to leak into the motor, and ruin the bearings or short out the windings. Water can wind up other places like in between the inner and outer door panels when the gasket around the detergent dispenser allows leaking. Sometimes the water can leak onto electrical components like the terminals on the dispenser or in a vulnerable place like where the wiring harness passes from beneath the door to the components beneath the tank. This is the place that the wires have to flex each time the door is opened or closed. If the insulation of the wires or the plastic guard that is supposed to surround the harness at this location gets brittle from leaking caustic detergent solution, the wires can short against each other or the frame. When this happens, the resulting short can burn a hole through the door's aluminum front panel before the circuit breaker trips, unless the breaker is rated for too high for the usual 15 amp dw circuit, in which case you can have a fire. Dishes should either be rinsed in the machine using Rinse & Hold or if they are throughly rinsed because it takes a week to accumulate enough dishes to wash, use the minimum amount of detergent in the main wash only.