Why would that warm-bodies scenario even happen? I think there's an assumption here that these tests actually provide a lower false positive rate than a solid experience check or whatever non-puzzle interviews do. After all, one stark difference to an audition for a ballet, is that you can't fake your ballet skills, however, memorizing CS stuff may actually be possible. Furthermore, the hard part to memorize are the things that would be asked in a good non-puzzle interview anyway.

Clearly there's room for pragmatism for such as interns, newly graduated, relocations etc.

Honestly, I think they're primarily filtering out based on themselves as the target image.