Though I doubt that, it might be true that being good in algorithmic puzzle-solving (as opposed to real-world algorithmic research/ development) helps employees in their day-to-day work. And I do think they maybe missing some real gems because of it.

But in my opinion, they just need an easily definable and quantifiable process. And they are happy to look the other way when they see covert cheating/ hacking as long as it clears the process. And there is no denying that there is still a decent ability threshold which most covert cheating people too will pass, which I guess suffices the corp needs.

I am a far bigger fan of pair programming after a basic phone screen, but large companies just can't do that.