A government could use it.

It could be very targeted (not enough to cause a riot but enough to silence the right people.)

It’s also a nice exploit for the bad guys, like ransomware gangs, Israeli “security” companies, etc.

They don't need to do it. It's the possibility of doing it what is already wrong. What happens if pedohitler decides that he needs to shutdown the phones for some bullshit reason before the midterms? You think apple won't bow and do as daddy trump says?

This is a major concern because it's written in the OS directly. It's not just something they install in your phone if it's a lease meaning that even if your phone is not leased, they can do it.

People would riot.

lol they would not. it is not convenient.