Sadly, I don't have a reference handy, but I recall reading a while back that there was this toxic culture at Microsoft in the past where one of the easiest or least frictive ways to climb the ladder professionally was to undermine others due to the way performance was evaluated. Basically, something of a “cull the lowest performing members” model.

Not sure if this is related or even reality, my memory wasn't so great even when I was young.