Well, I just burst into laughter.
First thing first: US vs EU. Keep that in mind.
But our dishwashers just fullfill all your criteria for a bad DW.
Silent: Check. (39dB is the quietest I have found, with a cycle designed for night use which tones down to 37dB.)
Small motors: Kinda. The secret is called inverter. As far as I know, the 39dB DW (an E-Lux made AEG) can run with motor wattage up to something like 150W, yet down to just about 50W.
Years and years to clean: Funny that Auto\Sensor cycles are doing the exact opposite. I've barely seen a sensor cycle extending time, and only on few occasions not cutting down.
Tines to close: 15 place settings on the 39dB AEG. Hmm. Dosen't sound bad.
No heated dry: I think heated dry was being phased out 20 years ago in the EU. Actually, the most high-tech dishdrying method comes from Germany and is called "Zeolith" (now redesigned into - I think they call it - "Zeolith 3D"), which is quite a fun concept made by BSH (Bosch). And somehow, we have dry dishes. Except for plastic. This sh** always stays kind of damp.
And I have yet to hear any complaints about such dishwashers not cleaning well. Except for the occasional loading error or stuck-on bit, NOT A SINGLE load I haver washed in a DW did not come clean.
And you don't need to be allowed to build DW or any other applaince. Just meet you countrys regulations, follow the law of your country and you can build a DW in any way you want.