It's not about storytelling but an interviewer usually wants to see how a candidate handles himself under pressure and asking such loaded questions is one way to do it.
I disagree with the assumption that asking loaded questions properly assesses someone's ability to handle a position where they are under pressure. It assesses your ability to do improv, but that's it. Someone can be extremely good at handling job related pressure, but shut down when asked to verbally answer a random question. The ability to think on your feet socially is very different from the ability to handle a tight deadline as an accountant.