Interviewing for a role is tricky by design. Not only does a candidate have to put a lot of effort into selling themselves and making sure they look like the best fit for the job, but they also have to face all the potential tricks that an interviewer might play to trip them up. As if the pressure of multi-stage interviews and pre-interview tasks wasn't stressful enough, facing a potential employer in conversation can prove to be playing office politics in expert mode. It takes experience to succeed, unless you already have your foot in the door.
Even those who have earned their stripes in the war of the job search can find that it is possible to be surprised by an interviewer. They are always finding novel and interesting ways to make potential employees feel uncomfortable in their decision to apply to a job. While it is important to challenge a job candidate who wants to take a role with a company, few are going to feel good about being employed at a place where playing psychological games is the norm from the interview stage onwards. It sets a bad precedent.