This. Classic problem with volunteer organizations. If you have the time, you can have formal meetings using Robert's Rules of Order, which are designed to force decisions by voting after discussion. But that's unwieldy within an operating organization.
The military is formally very hierarchical but, when planning operations, is much less so. There's a military custom that, when discussing a proposed plan, the most junior people speak first. (The elder Moltke is credited with this custom.) This, of course, is to reduce the tendency of people to agree with their superiors. More than that, it's to find holes in a plan before the enemy does. Once the decision is made, everyone is expected to carry it out fully, and not drag their feet, whether they agreed or not.
I totally buy this at the macro level. Just like open office concept saves buying a bunch of walls and more office space.
But Zappos? I think they have a history of making the "poor financial" decision to make employees and customers very happy. Seems very out of character to come form them.
As a DevOps guy with a great deal of startup experience I briefly worked at a hierarchy-less organisation and found it soul destroying. In the absence of any hierarchy decisions tend to be made by whomever can shout the loudest; projects go unmanaged; the needs of minorities (in my case long-term operational requirements for hosting the damn product) get ignored and appeals to reason with the company's owners were politely ignored.
My inner cynic wonders if founders love this fad because it saves the payroll they'd need to spend on experienced managers and absolves them of any responsibility to run the internals of their organisation, freeing them up to focus on overall strategy.
The result (admittedly based on a limited sample size - I'm not trying that again) was chaos. Real lord-of-the-flies stuff. One of the first questions I now ask when startups approach me is "what's your org structure like" - and if they haven't got one I run like hell.