To be fair, a lot of people get marketed a "Zettelkasten" because the creator wrote lots and lots of books, and this was seen as proof that the system works. OP didn't pull that out of his ass
To be fair, a lot of people write notes for the purpose of writing notes. Yes he did pull it out of his ass for a very, very tired critique of people who are into note-taking.
I'm not disagreeing with people who like taking notes. I use Obsidian myself (and I'm not weirdly triggered by this comment either). But watch any marketing video for Roam Research or anything adjacent to that and you will usually see people talking about Zettelkasten. In fact, I've seen lots of Obsidian users flat out say you're not actually building a Zettelkasten unless you're outputting original content.
It's not controversial to say Obsidian tool tweaking can be fun and productive, but could also tap into the exact wrong parts of peoples OCD brain.
No reason to be hostile for an observation of a community, especially as low stakes as "notetakers." I don't think they have a monopoly on taking notes?
The knowledge product of my notebook is the notebook. I use it to look up things that I wrote down previously. I also use the process of writing things down in it to guide my thought process.
No, they have not. There are likely far more people taking notes on paper, than there are people who are using Obsidian or similar. Especially when we are not just looking at the present world.