The following question popped up at the top of my mobile StackExchange app the other day: Designing a Coffee Machine
Without catching where it was posted before clicking on it, my thought was "what a great question for hitting on why multiple usability concepts are important in an everyday device!". Once I realized the question was on Code Review I was a little bummed, but the idea still stood in the head.
The type of question is somewhat abstract but I don't see it as any worse in that arena as many of the "how do I..." type questions.
For example: "How would I design a door knob/handle" - yields many great points on ergonomics and affordance.
For example: "Designing a Tea Pot" - may produce an answer that points out exactly why this is the most practical design ever (it'd be one heck of an answer to do so):
Would such questions be appropriate?