American dishwashers run very hot and use harsh detergents. Some dishes and cookware will state on their packing or even on themselves that they are not dishwasher safe.

Despite this, the sheer convenience of the dishwasher will make people ignore the warnings, and the objects retain their basic functionality just often enough that the meme can be an open-ended YOLO-like joke, phrased like parental encouragement, instead of merely mocking people who try it.