I work for a company that has a pretty great culture, even if it isn't quite as self-managed as Valve is, and what seems to be the common thing between the two

I work for a company that has a pretty great culture, even if it isn't quite as self-managed as Valve is, and what seems to be the common thing between the two is that both have a very strong sense of what their company culture is about, and both attempt to hire not just the best talent, but as much the best culture fits. To make something like this work, you can't just hire anybody. It won't work for many organizations simply because they have the wrong people with the wrong ideas of how to run a business or organization. It's also a lot of work to maintain such a system and the wrong hires can ruin it fast.