Comment by willywanker

What exactly is the threat model here of preventing Joe Nobody Famous or Important Poweruser from rooting the hardware they bought and paid for?

If someone has physical access to your phone, you have a lot more to worry about than mere root exploits. And given those who root their devices are far out of the profile of ordinary users, so a specially targeted hack like this is pointless as compared to the regular kind of exploits in apps that can target a wider base.