You make the (perhaps not very warranted) assumption that prowess at solving puzzles on a whiteboard is closely associated with a person's skills for efficiently developing maintainable software.
That this is an invalid assumption is the main argument against whiteboard interviews, so I'm somewhat surprised that you don't address that.
Thank you for your remark. It's in fact a questionable technique for developer evaluation. But with everyone learning to code, what's your take on the subject?
From my own experience, far more reliable information can be gleaned from questions like
What these kind of open-ended questions offer, is that they let you evaluate how your prospective team mate handles problems and to what degree their knowledge goes beyond textbook stuff and relates to the real-world practicalities of software development.
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.