I agree, especially to this: “If you refuse to define power structures, informal ones will emerge almost instantly. Not expressing these can be extremely harmful to your organization.”
Not having a “hierarchy” defined is dangerous because that means, they will emerge and stay under the radar — which makes them much harder to address and therefore potentially more harmful.
To me, there are three relevant answers to the hierarchy question (FYI, my background is sociocracy).
1. Hierarchy is necessary because we have to focus our attention to different levels of what it means to run an organization. 5-year planning has a focus that is different from ordering office supplies. Hierarchy is hierarchy of specificity of what we pay attention to. How broad or specific is our focus. 5 year planning is rather broad, ordering office supplies is very specific. Every organization benefits from a good hierarchy of levels of specificity because it sharpens the focus for what is needed on that level.
2. Having hierarchy of specificity is not good or bad, it just is. We have to get beyond the fact that there might be a moralistic judgement about people. All tiers of specificity are obviously needed to run an organization (otherwise we’d get rid of them). The basis for being equals in sociocracy is not that we all do the same thing, it is the principle of “no one ignored”. Everybody’s needs require equal consideration. There is another aspect to that: I, for instance, tend to be good at very broad levels of planning. But that does not mean I am superior. It just means that this is what I enjoy. AND: I only do that in SOME organizations that I am a part of. I can be a leader in one organization and be the “just tell me what to do” person in another. And that’s fine. I just don’t want my needs ignored where I am the “just tell me what to do” person. (BTW, We tend to pidgeon-hole people around their paid job which is a misconception. Some people lead global organizations in their unpaid time while doing very specific job in their paid time. That’s neither good or bad, it just is. We’re all equals but we’re not all the same. Trite, but true.)
3. The advantage of going from boxed job titles to “packaging” into roles is that I can hold several roles at the same time. I can be the one leading a team that does 5-year planning and be the person in charge of the office fridge at the same time. That’s what really appealing to me but I am aware not all non-hierarchical organizations embrace that. What roles I fill can also change over time. People might run out of steam for big-picture thinking, or they might react to changes in their personal lives. An organization with fine-grained roles and layers of specificity can react to that. We’re not assigning people to job titles but we’re assigning (several) roles to people.