There are two parts of this story.

1. Amazon has attrition metrics.

2. Hiring managers at Amazon are deliberately hiring weak people that they intend to later fire so they can protect the rest of their team.

The argument is that because managers can't actually unilaterally hire weak people that this strategy isn't really feasible.

There are still bad parts of #1, but that isn't the most controversial part of the story.

2. is not accurate. Managers don't have to hire weak people to satisfy the quota. People are rarely ever put into PIP due to performance. Most of the times it is political.

But that's the whole point of the "Hire to Fire" story. The claims being made here are not that managers are firing people to meet quotas, but that they are deliberately sabotaging some of their hires so they have a sacrificial lamb to fire.

Deliberately sabotaging people does not require that the sabotaged person be under-performing or low quality. That’s the point. If a BR prevents you from hiring an unqualified person to be a sacrificial lamb, then you just hire a qualified person that can get past the BR to be a sacrificial lamb. The existence of BRs is absolutely not a foolproof check on this.

You might ask “why would an HM fire someone who is qualified to do the job?” The answer is that Amazon requires that someone must be fired. If you were an HM, who would you rather fire: an existing qualified tenured team member who already knows the ins-and-outs of your team and system, or a new qualified person who would require extensive training and time to get up to the level of the tenured employee? You’re going to pick the new person, even if they are qualified.

Plus the existing tenured knows how to survive and navigate the politics. If they didn't, they would've never reached tenure. This is why the average tenure is so low.