There is no ideal food. There is an ideal shell. The difference is that the goals of a shell are well defined, and invariant to human preference. Human preference is real! But when it comes to computer systems it's rarely the correct variable to be maximizing in the optimization equation. The most wonderful property of humans is that we are adaptable: if a circumstance requires us to think of things in a model that isn't our intuitive choice, because the nonintuitive model produces better outcomes by the meaningful metrics, then we are capable of doing that! Our preferences are not these sacrosanct things that dominate the design calculus. They can and should take a backseat to other things when appropriate.