There are plenty of dishwashers with windows. Unlike the others devices mentioned, you don't need to see what's in there. The window is just for fun. They make you pay for fun.
Work at a dishwasher factory. We used to make a model with windows, they were really expensive parts, which meant that they were really expensive dishwashers for a feature that really isn't useful.
It makes sense in a microwave or oven because you can check in and make sure it's all good, or pull it out if it's done. You can't do that with a dishwasher, it just runs it's course.
Plus all you could see in the thing was splashing soap water.
How has no one mentioned the randomly capitalized words, space before commas, and just general shittyness of grammar? I find it hard to believe someone would write like that without consciously making it as bad as possible just so people would comment on it. And I'm in just as much disbelief that no one has said anything about it.
It's to hide the exploitation of the little gnomes that are enslaved in there. It's like most people enjoy a good steak, but nobody wants to see how it's produced. If you see the latter you're likely to become a vegan. Do you want to scrub your dishes by hand?
My first inclination was blender is critical to see progress as you set the time, ovens can see how brown cookies are but the dishwasher is a fixed cycle and who care... but then I thought about my washer and dryer both having windows for no reason what so ever.
Mine has a window and a light, but the light won't turn on until the dishes are done so you can effectively see nothing in there. The conspiracy continues!
There's a Technology Connections video where he cuts a hole in a dishwasher to install a plexiglass sheet. It leaked like hell, but you do get to see inside while it's running.