Examples
Problem
The board of a public company needs to replace the CEO after the old one was removed because of some unethical behavior
A manager is having a problem getting a few team members to speak-up during meetings and is unsure of how some of his ideas are landing
The people in a workgroup keep talking over each other during meetings
Culture-Solution
The facilitator tries to tell them that they need to, "respect each other's voice"
During the meeting, the manager occasionally asks one of the quieter people, "Any thoughts on this?" And outside of the meetings, encourages them to speak up
The board makes a commitment to the investors to "find a leader with the proper character and morals"
Rule-Solution
The facilitator introduces a "talking stick," and the only person allowed to speak (other than the facilitator) is the person holding the stick; the rule is immediately and rigidly enforced
The manager adds a "Reaction Round" process to the meeting that is defined as: "Going one-at-a-time, anything you have to add is welcome, and no cross-talk, responses, or interruptions until that person is finished"
The board restricts the authorities of the CEO position and adds some more checks and balances
Explanation
Notice that the manager's efforts in the strictly people-style are applaudable, but they take effort, which will be hard to maintain. On the other hand, a defined process like a "Reaction Round" avoids spotlighting any single person's contribution (or lack thereof), and the expectations surrounding it are predictable (i.e. not vague or ad hoc)
People tend to test the legitimacy of new rules (especially toddlers) to see "if they really mean it," which is why immediate and firm enforcement helps clarify the new expectation
It's true that human systems tend to work "good" when the people are good, but do you really want that to be the requirement? Can't even the best person have a bad day?