Companies encourage you to study for the interview, providing you with links to books, guides and preparation material. They'll delay the interview to give you time to study more. So it seems pretty clear to me that corporate management sees it as a test of study skills even if interviewers don't.
edit: I'm talking about large tech companies, not the startups blindly copying their policies with little thought or consideration.
edit: I'm talking about large tech companies, not the startups blindly copying their policies with little thought or consideration.