If you want feedback go see a therapist or career coach or talk to friends, family, mentors, previous coworkers etc. Don't expect a hiring manager to do this for you. As someone who has interviewed hundreds it would actually make me resent you because if you can't show the initiative or take the responsibility to improve yourself then I made the right decision not to hire you.
Worst of all I and many others would feel uncomfortable giving personality advice (if that was the issue) and would just lie and give some other reason. It's human nature and would just throw you off course and wouldn't help anyone.