I do get your point, but I think you have overlooked the heading of this post, “Getting Google to love you”.

Chris does ramble off the advantages, for the website users, of having a sitemap on your site. Some of which are debatable like you said, but his series of articles are focussed on Site Engine Optimization. Not so much pleasing your readers, but pleasing the search engines, which in turn send more readers your way.

I think pleasing the search engines is something everyone should wants to do. Therefore I would disagree and say this is meant for everyone.

Also with user journeys in mind, as a web designer one needs to cater to various aspects of the human psyche… like curiosity. Site maps are really only for sites which are either very complex or used for business purposes where the user needs to access content in less than two clicks and not get lost in a maze of irrelevant content.