HN is read by people with an interest in and understanding of computers. Many of them are either looking to employ people or to be employed. There's a natural match-up there.
But if there was a HN jobs forum it might soon become dominated by people not like us ("us" meaning HN readers/posters). This would seriously devalue it as a place to find high quality jobs and high quality workers.
So how could thisd possibility be countered? One way might be to have a "secret" that people who post to HN typically know or could easily find out.
For example there was a Usenet newsgroup (I forget which one -- alt.sysadmin.recovery perhaps) where the only way to post on it was to forge an approval header, and disclosing this secret was disapproved of. Of conser a recent job posting to getacoder which involved solving the Halting Problem ( http://news.ycombinator.com/item?id=376238 ). There could be something like that on the system and anyone who takes it seriously reveals themself to be clueless and doesn't get let in.
Or maybe you could have a forum that has tow levels of membership, one for the clueful (who can post jobs for free) and another for the clueless (who must pay). People looking for jobs get to see which jobs are posted by the clueful and which are not, only if they themselves are clueful. And how to become a clueful member is a secret that (i) only True Hackers can work out for themselves, and (ii) it is forbidden to communicate with others.
