They certainly don't filter out toxic people who make others leave companies because they poison the well.

I have a suspicion that "good candidate" is being gerrymandered. What might have been "good" in 1990 might have become irrelevant in 2000+ or perhaps detrimental. I say that as someone who is actually good at algorithm questions himself. I think GP, as well as other Google defenders, are parroting pseudo-science.