* Either a /static/ image or colored text
* Normalized (re-packed, stripped of all other data, etc)
* Vetted by a human somewhere to not be 'misleading in appearance' (not checking facts, but making sure that it doesn't look like a download button or anything else not obviously an ad)
* Based on the content of the context and nothing else (you can bake them statically based on the story and/or comments thread on the page)
I don't think shifting responsibility to publishers is the answer. A half-serious idea would be to have a neutral regulatory body issue "licenses to advertise" but how long until corporate interests took that over?
I read it as a measure of their financial desperation. They're eating their seed corn (their reputation is their most valuable asset in that without that, what else do they have?), and, well, what other choice do they have? HN has been talking about the other choices for years, but every time I see someone try one, they sink.