If I am an HR, I would have no obligation to tell the applicant the reason/s why he/she is not selected. Impression plays a big role in hiring an applicant. For example, there are 5 applicants that are equally qualified in terms of education, experience, scholastic records, etc., talks great during interviews, how would you select among them is by impression. attitude is a big factor to impressed an employer. if you are not selected because of some impression or an employer is much more impressed by the other employee, then there is no need to tell you that reason.
Attitude really matters. Please don't appear to be very demanding as it's a big turn-off to employers.