I agree with all of this. I also think Medium is a social media site (as is HN), guilty of the same things the author calls out.
The upvoting of submissions is needed to 'crowdsource' an interesting front page.
You might do without the karma reputation system, but that will have negative impact on the quality of discussion. After you passed the first treshold (downvote privilege at karma 500) there seems to be no value to the system (no further privileges). But (forgot the game theory name) the 'punishment' of a downvote + karma decrease is probably a great help against shitposting.
Is there a right way to set things up, and maintain high community standards and comment quality?
Edit: Was it Loss aversion?