When they try to reform without first having gained trust.
We've all seen the tremendous waste of resistance to change, when a leader wants to change things for the better, but every one else holds back, soldiers on or even sabotages. We see it at company level, we can see it now at country level. Some times, resistance is so strong it can derail (or at least bog down) the entire reform, and some consultants have specialized in this one single issue: overcoming resistance to change.
When the leader is strong, and resistance is everywhere, leaders tend to retreat to a bunker mentality and force the changes through, not matter what, at increasing costs to all around. They can't understand why people simply won't see that their "solution" is better, necessary and urgent. We need to reform education now! We need to reorganize the company now!
Leaders themselves create the resistance whenever they push changes through without having made the effort to gain people's trust first. This is one of the tough lessons I learned from my mentors, Dan Jones and Jacques Chaize a decade ago. Having worked a lot in the auto industry, I believed that you had to expect resistance in any case, and drive changes through no matter what. It might work in the end, but at what cost?
Now, when I work with any new facility, I start with a kaizen ergonomics first. Managers are taught to do frequent, short, workshops with their teams to support team members in fixing obvious ergonomics issues. They help where they can, not by managerial advice, but by getting support from other parts of the organizations. Before anything else, they build mutual trust.
Where managers succeed, all the other changes brought by pull systems, improving flow and red bins and so on happen seamlessly, and sometimes even enthusiastically by engaged team members. The lesson is that improvement can only happen within a relationship, and you have to build the relationship before driving reforms, so that every one has a chance of seeing their interest and contribution, as well as a chance of changing things where they don't understand what the reform is supposed to achieve.