What actually resonated with me in the first of two rants is this:

“…It is important to write properly, i.e. with words that mean the things you’re trying to say, with punctuation used as punctuation and not decoration, with sufficiently correct grammar that the reader doesn’t have to put in serious effort to understand what you’re even on about.”

Emphasis mine. It’s accessibility. They’re describing a form of accessibility.

https://guinevak.bearblog.dev/two-rants-for-the-price-of-one/