If you take the tweet at face value, being dinged for a whiteboard exercise is pretty silly. But people do get hired for specific roles and just having demonstrated you're great at X doesn't mean you should clearly get hired for an only somewhat related Y.

I like to think I'm pretty good at certain things but that doesn't mean I'm a good candidate, especially at a senior level, for lots and lots of roles that, while somewhat related to my skills, aren't really in my wheelhouse.