If companies receive comments saying i never heard back (at least they need to generate an email saying application was received and later your not a good fit, if not) and they keep posting this same or similar job. Well then they should warned about losing their HN job listing priviligies. Put them on a list that a bot notifies you and or downvotes them a lot.

Those who comment and are to be taken seriously will have a certain amount of karma and or history on HN.