The author's main point is "When you override this expression, you’re indirectly communicating that someone’s personal preferences are less important than your own visual sensibilities" but that's always be the entire point of CSS. The browser comes with default styles, the user can override those, the website can override those overrides, and then extensions can override that. Granted, very few users probably do override the browser default styles due to those defaults rarely getting used anyway given the prevalence of websites doing so...

Also interesting that the author makes no mention of the ability for the site to set the color of the address bar area for Android browsers. Seems like the same gripe should be had.

Aside: I find it funny that the author says "This phenomenon is why checkboxes use squares and radio buttons use circles" and then links to a page for the reader to find out more, in which the prominent photo is of a radio with square pop-out buttons.

But a good read nonetheless.