That yes, but I also just mean that the web site of a thing must be allowed to promote the thing. It's the one place on the net where that is not an ad. So anyone who wanted to say "I find this thing interesting", they have to point to something, and the best most difinitive place is the thing's own home. It will automatically always look like an ad, and yet that one instance of the promotional material somehow can't be called just an ad, or guilty of any of the things you don't like about ads.

The same link to the same home page would be an ad if HN had inserted it instead of a user.

It would also be if the user were a bot or spammer and there was no possibility that the subject was actually interesting.

That last is subjective but I personally think it's a cool topic, and topical enough in the context of HN. Rather that than yet another ai optimized micropayments processor in zig