I think you're missing the point of that comment. Yes, you don't want to hire someone to a programming role if they have absolutely no skill or knowledge in the subject and "cannot we write a loop". But that will become quite clear during the interview regardless if you have them doing some leetcode challenge or not. The important part to me is whether they can function in the present team, whether they can employ problem solving skills in a positive way. Sure, let's whiteboard out a problem, show me how you think about it, how you approach it, what steps you take to disassemble it. But also, if you're stuck do you ask for help? Can you discuss the problem without having a solution ready, do you have ideas about how to research it, can you present paths to progress? These are the really important attributes, not "have you memorized this wacky algorithmic solution in the last two weeks". Pure whiteboard tests are just stupid, don't shed light on someone's potential, and carry a context that makes a lot of intelligent high potential individuals freeze up. They select for the wrong traits.