I know people who would probably ace quite a few rounds (basically until they get asked some soft questions about architecture) who really don't know much about the fuzzy boundary between the algorithm textbooks and actual practice or even just having thoughts about the field full-stop. Curiosity is not a given.
Similarly I also asked someone I know who wants to a do a PhD in economics what he thought about the current macroeconomic situation in the US and he had no thoughts at all.
A lot of theoretically smart aren't like people who comment on hackernews and actually have intuition (or a penchant for meaningless speculation...)