Earlier quoted context omitted.
Ha! This is a really interesting perspective—I think you're saying, "it's all plain text, so there's no advantage to using Markdown instead of docx". I think others have an opposite view, but on the same grounds. The argument seems to be: it's all plain text, so docx is overkill, so markdown is more technically efficient! There's some benefit to using the tool I know best (emacs, for me), so it's nice to use a "nativ…
The benefit is the rest of the pure text toolchain. Like being able to use Git. I can confirm, for example, how long a typo has existed in my book by looking at the Git history. Maybe that's a bit academic, but you get the point. I have the complete history of everything I've ever written. Another example: because formatting is reified in Markdown, I can grep for it. Did I misuse italics? With one command I can find…
And, find-and-replace for specific formatting is supported out-of-the-box.
Finally, cmd-i / cmd-u / cmd-b are pretty easy default bindings, and setting up shortcuts for more intricate, specific styles is straightforward in Word.
I share your preference for using an efficient tool—I'm a die-hard md+git practitioner. But the "most people I know" argument is not a good basis for rejecting real, rich features in software that works well for other people.
I am also curious: why do you care about semantic correctness? It's OK if that's just your preference, but it's not something that moves the needle for me....I'm not sure why I should care!
(edit to add: my comment sounds glib and a little sharper that I intended. That wasn't my intent!)