5) The knives can cut the plastic coating on the dishwasher tray/rack and then the inner metal starts corroding. Don't ask how I know… As for your fourth point

5) The knives can cut the plastic coating on the dishwasher tray/rack and then the inner metal starts corroding. Don't ask how I know… As for your fourth point, soft metals sharpen in a few seconds. My high carbon steel knives will slice right through tomato peel without smashing the tomato itself; or cut raw meet in one quick movement.