It's okay to filter people out who are too uninterested to click a "Documentation" link yet vocal enough to come post about it.

It works for https://www.midjourney.com/home and apparently this project too with its 1100+ upvotes.

No, it isn't okay to filter people out for giving helpful feedback solely because you don't like the feedback.

It's especially not okay to be so rude on HN. "Please don't post shallow dismissals"

I would think, or hope, that this guideline is geared towards protecting a years-long effort such as writing a performant, feature-rich terminal emulator, rather than a comment which takes 5 minutes max to draft.

Not clicking on a documentation link on a technical project is the definition of a shallow dismissal in my opinion.

No. The rule is about protecting a culture. Having a brief description on the front page is an eminently reasonable suggestion. Mitchell's response was a shallow dismissal of the person (calls out "you" five times in six sentences) and was against site guidelines.

Which culture would that be? Starting off a post with “I hate things… this is one of them”?

I think the discussion here would be different if the tone was more moderated. Seems like you’re dying on a hill for the right to be abrasive without consequence.

The original commenter posted a shallow dismissal by putting the effort into posting a comment without clicking a single button on the page :)

No. He didn't post any kind of dismissal at all.

The feedback provided wasn't helpful. You're absolutely correct in that shallow dismissals aren't kind, but you're wrong about who was shallow and who was not. OP didn't dismiss anyone, nor was their comment shallow. And they don't owe you or anyone else anything as far as "explanation" goes, and they can filter out whoever the hell they want. Click the link and look further, or don't.

Meanwhile, dr_ketyn's comment was both rude and not constructive in the slightest (here's a tip: starting feedback with "I hate this" isn't constructive or kind).