Agreed. My advice would be to cultivate an environment where a subordinate can speak up and challenge a manager and not be threatened, fired, or feel like speaking up will hurt that person's career advancement at the organization.

And I'm not only talking about issues where a non-technical manager critiques a technical project. If a non-technical manager has a comment about a UX choice, it should be valued not because it came from a "boss," but because it came from someone who did not make it. Something that seems really obvious to the implementer will not always be obvious to the general public and that is where non-technical feedback, even from your boss, is valuable.