I usually gave an indirect answer when interviewees asked. For example, when hiring part-time employees, most of whom were current college students, all I really cared about was their ability to show up on time, follow directions, and be familiar with standard business practices. So anyone who showed up late to the interview, wore inappropriate clothing for a business setting, answered cell phones during the interview, etc. was cut. If someone asked why I would usually frame it as "I can't discuss the decision to hire or not hire you specifically, but generally companies look for candidates who show up on time to an interview, dress appropriately, and don't answer phones, etc."

Alternatively, if you ask you might get a comforting lie. "We were really looking for someone who had more experience with specific skillset X" rather than "We hated you, we think you suck, and we all laughed behind your back after you left".

Of course, a comforting lie might be what you actually want.