I've seen a series of these types of articles, and I'm not sure if they're trying to make the next linux or doing it for fun.

One problem to me is drivers, drivers, drivers. Linux has a bunch of 'em. Other operating systems, not so much.

This particular series is more of a toy OS for learning purposes (and through which they can teach things). At least, that's my impression of it.

Redox (https://github.com/redox-os/redox) is a Rust OS project that's aiming to actually be a usable consumer OS.