Essentially, developers with substantial domain experience / familiarity with the problem space tend to do what they think is best, instead of following orders.

Accepting the value of that behavior requires a great deal of personal and organizational maturity, especially when you want to try something out quickly and your developers refuse.

Sample phrases include: "Why did the customer ask for that - it sounds like our planned implementation won't satisfy their goals", or

"Won't this change mean we operate at a loss to subsidize your other company, which will affect staff bonuses".