@David8433 Some guests seem to come from outer space and are clueless as to appliance use. We had a wonderful Bosch dishwasher in our vacation home until a guest put a bristle brush down it. We now install less expensive, simple, mid-range dishwashers in our properties. We service them twice a year, i.e., pull out the spinners, traps and screens and blow out or replace the water and drain lines. Similarly we clean out the sink u-traps and snake the drains (kitchen and bathrooms) twice a year. With this maintenance we have avoided most dishwasher issues.
With that said, we have one property that has had 4 dishwashers, 3 refrigerators, 2 ovens and 3 sets of washer/dryers in 10 years. We have yet to figure out why certain guest group demographics are so hard on appliances. We continue to accept them, but fear them.