http://blog.interviewing.io/no-engineer-has-ever-sued-a-company-because-of-constructive-post-interview-feedback-so-why-dont-employers-do-it/
^ What he said
Maybe the best recruiters are the ones who have been Software Engineers before. Maybe it is a bias on my part. The blog posts around their experiences are gold.
Companies need to do better at giving feedback or they really should not expect candidates to give any feedback when asked.
P.S. I am not interviewing anywhere currently. Busy creating my own product.