Comment by oarsinsync

Rosetta 1 delivered 50-80% of the performance of native, during the PPC->Intel transition. It turns out, you can deliver not particularly impressive performance and still not ruin your app ecosystem, because developers have to either update to target your new platform, or leave your platform entirely.

You can also voluntarily cut off huge chunks of your own app ecosystem intentionally, by giving up 32bit support and requiring everything to be 64bit capable.

...because users have no other choice when only one vendor controls the both the hardware+software. They can either use the apps still available to them, or they can leave. And the cost of leaving for users is a lot higher.