I think, it comes from a general frustration, because the YouTube comment section is practically unusable for actually discussing a video.

Every so often, I watch something and want to see what people are saying about a particular section in the video. Like, maybe I was hoping for some info in the video and expect someone to have posted it in a comment instead.

But then I have to scroll through tons of comments like:

• "First!" (Followed by people telling them they're not actually first.)
• Various comments about how they're watching the video shortly after its publication. Or long after its publication.
• "What an inspiring video! Blah blah blah..." (with a profile picture of a half-dressed lady, because it's actually just a bot)
• A verbatim quote of a funny sentence in the video with nothing added.
• "Just commenting for the algorithm!"

Like, I don't want to hate on people commenting what they like, but it's just frustrating in that situation, because you do have to read every comment, to make sure you're not missing something. You just become acutely aware of every repeated joke and every single comment you had to read, which did not actually say something.