The writing of history (historiography) is not meant to be a minutely detailed account of everything that happened. History is a narrative, a story about how we came to be here, and sees the past with a particular lens. I think this particular history was meant to bring appreciation of influential yet obscure and niche languages for the current generation of developers and software engineers. I doubt it was meant to be definitive or exhaustive.

In fact, at the very bottom of the article, there is a link to the Encyclopedia of Programming Languages with over 8000 entries. The influence of Smalltalk’s “everything is an object” on Objective-C and Ruby is probably in there somewhere.

Disclosure: I wrote Ruby professionally for over ten years, and learned the basics of OOP with ObjC back in the 90s. I get the significance of Smalltalk’s object model.

> The writing of history (historiography) is not meant to be a minutely detailed account of everything that happened. History is a narrative, a story about how we came to be here, and sees the past with a particular lens.

Of course I get all of that; however, the author also chronicled the influence of these languages and certainly Objective-C use of Smalltalk's object model, a language that provided macOS and iOS such a competitive advantage for many years, it's probably worth a mention.