The person writing this is confusing their personal opinion for objective UX fact. It is commonly accepted that only highly organized users use features like tags. The vast majority of people simply don't. Rather than jumping to the conclusion that this is hostile it's possible Chrome and Docs just have a wider user-base than this particular author.
I don't even think it's about organization, more aesthetic sensibilities. Why would anyone want to have special folder icons? "Because it looks nice" is the only possibility that occurs to me. I probably have over 1000 bookmarks myself, but I can't think of why I would want to "tag" a bookmark. Tags can be useful for finding new content, but if I bookmark a sit I probably know enough about it that I wouldn;t benefit…
I have 8000+ bookmarks.
https://pinboard.in/u:eitland/
I can mostly find anything I want within a few minutes. Oh, and I pay for archiving so there's a chance I can read it even if the link rots.