It's hard to argue with, especially if you've experienced using good documentation. OpenBSD's man pages are one example. It takes a little time to break the habit of checking Google first and instead checking the man page first (you eventually learn that you rarely need more than that).

The key word is "good" documentation. That takes time and effort to write, and it takes time and effort to keep it updated as things change. As the author notes, it will have to be something that is made part of the culture of the organization. And given that recent agile programming approaches proclaim that "the code is the documentation" and that formal, separate documentation is an impediment to productivity, you'll find that many developers will dig in their heels if asked to write documentation.

Bad, outdated, or just plain wrong documentation can be worse than nothing, as it tends to lead you to incorrect conclusions and beliefs about the system.