Experts undoubtedly agree on many points. The fact that they have differing opinions—and indeed should have them—is part of their craft, something on which they are in complete agreement, regardless of the field in question.

Here's an example: A craftsman knows what a nail is, but how, when, and whether it should be hammered in is a matter of judgment.

Edit: To put it more clearly: Someone who doesn't know what a nail is has no say in whether it's a good decision to use one.

That’s not to say that the opinions of laypeople don’t matter, since they may very well be affected by the issue. My point is simply that nothing is less productive than someone trying to tell a craftsman how to do his job without having even the slightest clue about the subject.

In this analogy, imagine a client who hires craftsmen and stands behind them the whole time, offering his uninformed opinions on everything they do—that only shows a lack of respect for the work of experts; it’s absolutely counterproductive.

It would make much more sense to clearly state what you want and simply let people do their jobs.