I think talking about documentation is important because it's really the key to helping people understand code, and therefore maintain it. I think the idea behind self documenting code is nice, you should write code that is easily understood, but it falls short of being useful for the broader organization on a few fronts.
I have found in longer existing organizations discoverability of the existing code is a lot more difficult than searching for the human readable documentation equivalent and when even that is not a problem there's no real consensus on what clear and simple code is but even if the documentation isn't written by a strong writer it's easier to understand the system still from that documentation than by code which may have been written in a similarly confusing manner.
Of course if no documentation exists, such as what I've experienced, my point is moot, but then other issues are sure to abound.
I've heard a story recently about one of the larger brokerages in the world back in 2008 almost not being able to repair their login and authentication systems and when they did it taking a significantly longer time because no one had documented the system and that's terrifying to think about.
