[Grustaf]

People who hate whiteboard interviews are probably the same kind of people that say things like "why do we have to learn multiplication in school, I can use the calculator app."

As others have pointed out, the idea is to provide a context where you can judge the candidates knowledge, intelligence and ability to explain their thinking. Whiteboard tasks happen to be a good way to do that.

When the interviewer asked me to implement a depth first search algorithm on the board (although he didn't call it that), it most definitely wasn't because he thought that I would ever need to do anything like that. That's why they accepted me even though I didn't quite nail it. That's why I never worry about memorising algorithms, that's really not the point.