It's been said Valve is somewhat like high school with their completely flat hierarchy, although this is never mentioned in the many articles praising their management structure (or lack thereof). I'm curious if this type of management system causes similar problems.

That being said, everyone is different and some people (and cultures - Germany, Switzerland) function in a hierarchy very well, while others don't. I think the article alludes a little to this with the comment about individuals who take initiative vs those who don't. IMHO, those individuals who take initiative on their own are drawn to entrepreneurship and small companies, whereas those who don't are drawn to large corporations where others can set goals for them and as they achieve those goals, they move up. As Medium grows, they're inevitably going to attract more of the latter type, and it will be harder to provide meaningful roles for the former type.