So, on verbosity: that’s a stylistic choice. Not for everyone. For romanization: point taken and I agree frontloading it would’ve been more elegant. Though I kind of don’t like that it sounds wrong for an unprepared speaker.
For correctness: please provide specific issues. I’ll try to fix them. This is the part I actually care about.
For completeness: yes, some things I put out of scope break the pattern (or rather extend it — the mechanism of concatenation is the same but it actually may be easier to hard-split it by godan/ichidan). I genuinely think that by the point you learn those, you don’t need the scaffolding anyway, and the model has done its job.
I don’t feel like shit from the feedback. This is not my first rodeo. Where I have correctness issues, I would like them pointed out so I can fix. The handwringing about it being a weird way to teach — not so much. I know it’s weird; I wrote it because that’s what worked for me.
And fighting out the criticism in HN comments is half of the fun, isn’t it? :)
Again, the conceit of the article is you can learn almost the entire conjugation system in a single evening with no prior knowledge of the language. I invite you to step back for a moment, to accept that conceit as valid, and then to judge the article based on that conceit. For a serious learner, think of it as a fever dream that helps the concepts click next time you see them “properly”. For a tinkerer, think of it as a spark that gets you curious about the language.