Not least because a lot of these things are things that novice writers will have had drummed into them. E.g. clearly signposting a conclusion is not uncommon advice.

Not because it isn't hamfisted but because they're not yet good enough that the links advice ("Competent writing doesn't need to tell you it's concluding. The reader can feel it") applies, and it's better than it not being clear to the reader at all. And for more formal writing people will also be told to even more explicitly signpost it with headings.

The post says "AI signals its structural moves because it's following a template, not writing organically. But guess what? So do most human writers. Sometimes far more directly and explicitly than an AI.

To be clear, I don't think the advice is bad given to a sufficiently strong model - e.g. Opus is definitely capable of taking on writing rules with some coaxing (and a review pass), but I could imagine my teachers at school presenting this - stripped of the AI references - to get us to write better.

If anything, I suspect AI writes like this because it gets rewarded in RLHF because it reads like good writing to a lot of people on the surface.

EDIT: Funnily, enough https://tropes.fyi/vetter thinks the above is AI assisted. It absolutely is not. No AI has gone near this comment. That says it all about the trouble with these detectors.

That won't entirely weed out these tropes, but it will massively change the style.

Then add a few specific rules and make it review its writing, instead of expecting it to get it right while writing.

To weed out the tropes is largely a question of enforcing good writing through rules.

A whole lot of the tropes are present because a lot of people write that way. It may have been amplified by RLHF etc., but in that case it's been amplified because people have judged those responses to be better - after all that is what RLHF is.