Why? If people cant answer questions about a job post there is something wrong. I criticised a job post on a mailing list fairly brurtally and got it much improved, and had positive feedback. Hopefully they got a better person for the job. I see the posts here and would never apply to many with the strangely asymmetric thing of no comments. It could at least be an option to have comments.
Don't you require some sort of "trusted" status to post a job? I think that level of trust would mean the same accounts should be able to moderate their own postings.