[vvvnnnnvvv]

That may be the public way of explaining it, but I see it slightly differently. Amazon doesn't like "good intentions", rather it prefers "mechanisms". We all know that managers should put low performers on PIPs, but Amazon doesn't really trust managers' good intentions. It wants to make SURE that low performers are put on PIPs. The mechanism they've selected is an unregretted attrition target. The target represents the number of people they expect to be under performing and only applies to orgs greater than a certain size.

source: recently left Amazon as SDM