Being able to use vim at a basic level doesn't really take all that long to learn. Sure, there's the memes about vim being impossible to escape, but it's really not that hard to learn how to do so.
the cruel part is that it adds to the candidates nervousness. so i avoid that, but otherwise i agree, especially if it is a modern version where arrow keys and backspace work in insert mode, so one doesn't even need to use command mode to make corrections.
I learned vi by being too lazy to change my default editor in git..