We will have perfected it when you can again expect them to last 20 years without failure and at failure there is a diagnostic code that tells which reasonably priced part needs to be replaced.[1]
They are probably optimized now, but not for the consumer's benefit.
Also, people's thoughts on dishwashers vary hugely with the number of people in the household. When I am alone I never use a dishwasher. When in a household of four, always.
EOM
[1] As near as I can tell from family experience, the difference in reliability between the high end brands and the normal brands is that the repair parts are more expensive on the high end.
It's fun to chase consumer benefit in a circle. At least some of the drive towards more features and low upfront price comes from consumers giving more weight to those aspects of the design (rather than reliability and lifetime cost).
I would still agree that cost optimization has certainly done its part in trampling all over maintainability.
Not to plug or anything, but our Miele dishwasher is still working fine after 18 years, and the clothes washer only required a cheap fix a couple years ago.
That said, they're definitively more expensive. We only got them because they came with the house.
My dishwasher was broken for months - never got around to fixing it - and the reality was, it didn't take noticeably longer to clean up after a meal or after a day's meals. Might be different if you have a big family, but from what I remember growing up, the actual washing of dishes was the least time consuming part of cleaning up.
