I don't mind explaining algorithms on a whiteboard. I do mind having to recall arbitrary algorithms on the spot. Even then, you can avoid asking trickier algo

I don't mind explaining algorithms on a whiteboard. I do mind having to recall arbitrary algorithms on the spot. Even then, you can avoid asking trickier algorithms as an interviewer. But as soon as you have to write in an actual language it just becomes too painful. Which is what most interviewers expect.