What's the issue with everyone saying that pre-cleaning is something effortful? Spending a few seconds to rinse a dish right after use saves you tons of effort later on. If you leave your lunch plates in the machine for a day before turning it on, chances are that even a decent dishwasher can't get all the gunk off. You'll end up scraping the rest with your fingers. I don't get it why all the dishwasher ads tell you…
The dishwasher takes a small amount of (very hot) water and cycles that same water over everything many times. I don't really want a lot of sanitized (or not) food bits going over everything, or clogging the debris filter, thanks.
Fun fact, some 'dirt sensing' dishwashers sense dirt by using a resetable undersized fuse on the circulation pump. The more gunk in the water, the harder the pump works and the more it triggers the fuse. Count the number of activations to see how dirty the dishes are.