The author would do well to look up SGML; Markdown is fundamentally about sugaring the syntax for tag-oriented markup and is defined as a superset of HTML, so mistaking it for something like TeX or Word really demonstrates a failure to engage with Markdown per se. I suppose that the author can be forgiven somewhat, considering that they are talking to writers, but it's yet another example of how writers really only do research up to the point where they can emit a plausible article and get paid.
It’s worth noting that Microsoft bought PowerPoint, GitHub, LinkedIn, and many other things—but it did in fact create Word and Excel. Microsoft is, in essence, a sales company. It’s not too great at designing software.
So close to a real insight! The correct lesson is that Microsoft, like Blizzard, is skilled at imitating what's popular in the market; like magpies, they don't need to have a culture of software design as long as they have a culture of software sales. In particular, Microsoft didn't create Word or Excel, but ripped off WordPerfect and Lotus 1-2-3.
From the perspective of somebody who's actually hacked on Linux: Most Linux maintainers, like most programmers in general, are full of machismo stemming from the inherent difficulty of writing C. It is extremely difficult to write correct C and nobody can do it consistently, so those maintainers are heavily invested in the perception that they are skilled with C. Rust is much easier to write and democratizes kernel hacking, which is uncomfortable for older maintainers due to the standard teenagers-vs-parents social dynamics. Worse, adapting various kernel interfaces so that they are Rust-friendly has revealed that the pre- and postconditions of interface methods were not known before; there is existing sloppiness in the kernel's internals which is only visible because of Rust-related cleanups.
Note that Linux is not a GNU project. GNU's kernel project is GNU Herd. "GNU/Linux" refers to Linux userlands populated with GNU packages. It's important not to be distracted by this; the kernel is agnostic towards userland and generally is compatible with any loadable executable that uses Linux's public syscall interface, so the entire discussion of Rust in the kernel is separate from anything going on in userland.
Most siblings are wrong! PRs written in Rust can be rejected. There are already multiple non-C languages in the kernel. Rust is sufficiently available on the platforms where it will be required for building kernel. Maintainers are only added after they have shown themselves to be socially reliable and they can be removed by other maintainers if they are unresponsive. The only correct sibling points out that Rust is different.