>But preparing for an interview by cramming/studying material that is supposedly needed for the job makes no sense. A candidate should have the experience to do the job well.
I think it is a good ideological stance. However, what about the scenario when you are applying for a junior position and don't have that much experience?
Moreover, as it has been demonstrated time and again, technical hiring is broken. Some folks like to talk about high-level concepts; some folks like to ask trivia and some others like to ask you to whiteboard the algorithms. If a company expects you to use a whiteboard and you are not used to it, you are not going to do well even if it is a topic you are familiar with (We don't realize how much we rely on editor/autocomplete).
I am happy that he was able to find another job without preparing, but this advice will not work for the majority of people.