To be honest, this seems to me like a pretty bad take with weird and kind of BS arguments. Why are professional designer, both those working for some of the biggest tech companies and those working in open source project, making these choices? It couldn't be for actual reasons or because they actually prefer it like that. No, they are "afraid of color". Or implying that dark theme exist because of these black on white themes, as a mean to escape it. It just weird backwards logic to justify his taste and shouldn't be necessary to just state that he prefer a different kind of themes.

To me, the Windows themes he showed as positive examples look way to cluttered and busy, even though they don't show this much information. I don't need the theme to be "exiting", I need them to display the information in an easily readable way. And dark theme aren't there just for people who dislike the modern light theme. Having a light and a dark theme (and ideally having the app follow your system preference) actually serves a purpose. You can actively switch between them depending on the context, the time of day, the brightness of the room or any other reason to make the screen easily readable and comfortable to look at.