Do hirers give feedback? When I was suddenly dropped from dropbox's interview process, and asked for feedback, I didn't get a response until my friend working there went and bugged HR, and then the response that did get sent was "we have no comment".
Sometimes. I interviewed a LOT out of college and often made it to 2nd and 3rd rounds. Every time I got rejected, I would pop an email to the HR rep and ask for feedback along with something like "thanks for the opportunity." Maybe 1 in 10 would respond and some 1 in 15 would actually give me feedback on how I did. So while it's a fairly low chance shot in the dark, you don't have much to lose by asking. Just be polite.
Generally no. All it does is open up the possibility of lawsuits and invite an argument. If you tell someone they were dropped from consideration for reason X then you invite the applicant to rebut that reasoning. But the truth is that the company has decided not to proceed and there is nothing the applicant can do about it. Thus folks who have been around the block a few times simply say, "We've decided not to proceed" and leave it at that.
That is a sad thing but I don't think it will change.