number 1 is pretty useful feedback for me, if they don't respond to people who apply I don't intend to take time to make a good cover letter and adapt my CV to highlight how I would be a good fit for the job.
As a hiring manager I can assure you that is not always practical. If someone makes it to an interview, even if it's just a first stage telephone interview, then I'll readily give feedback. If some sends a CV and then asks for feedback then I will also happily provide feedback if time permits). But recruitment is a heavily time consuming process already and some positions can receive dozens or more CVs so I don't have the time to reply to every single candidate and explain to them "Thank you for applying but unfortunately we've had better CVs through." Likewise I've never expected that when applying for other jobs either.
[edit: before you read on bare please in mind I'm not advocating comments be enabled (like many others have assumed).]
I think it's a little redundant making a distinction between "useful" and "interesting" because either way the comment has value. However I do agree with the points you made in your other comment (https://news.ycombinator.com/item?id=22767319) and that the examples given of useful/interesting comments by the GP doesn't offer a high enough value to justify the inevitable negative and other low value comments. Which I think is the real crux of the matter. Much like why political discussions are generally banned on here, the signal to noise ratio just isn't worth the few valuable comments a submission might receive.
And posting in any of the "Who's looking for work" threads mostly just results in lots of people sending you emails:
"We saw you post, would you like to join our platform ..?"
Lots of upwork knockoffs; I've started sending them GDPR Subject Access Requests to see what the companies have scraped and held about me. Next step is obviously data-deletion requests. Fun.
They're not supposed to do that, as the rules at the top of the thread make clear. Perhaps we should build some kind of 'flagging' feature so people can report bad actors. Then we could add a warning that bothering HN users illegitimately will land them in the bad dog box on HN.
