It may not seem to make much sense on the surface, but companies have sound business reasons for prohibiting interview feedback. The most obvious reason is to avoid liability. If a candidate feels they were treated unfairly or discriminated against because of feedback they received, they may bring a lawsuit against the company.
Another reason is to save time. Companies that try to provide feedback to candidates must invest extra time in collecting and delivering it.
A third reason is to ensure all candidates are treated equally. Allowing feedback to flow naturally from recruiters and interviewers to candidates means that some candidates will receive more feedback than others. It’s not exactly formulaic, and how much feedback you get depends on many factors. Restricting interview feedback is an efficient way to remove this potential discrepancy.
Lastly, some companies restrict interview feedback to avoid having to deal with unhappy candidates. Obviously there will be many cases where a company decides a candidate isn’t a good fit but the candidate just doesn’t agree with that. Not only does this result in more time the recruiters must spend on the phone or e-mailing with candidates that they’re already done with, but it can also reflect negatively on the company on review sites such as Glassdoor.
So the third thing I want to be clear about is that I don’t think companies do this without reason. Companies are completely within their rights to have policies restricting interview feedback. These policies do provide value to the business and mitigate risk.