I haven't thought about it much, but I don't see why you need to give the government full unfettered access (or any access) to implement a kill switch.
The customer with a private key? (...with no way it could be activated by the phone manufacture/service provider/legally forced by governments.)
Probably not, because it's not user friendly enough, or some excuse. It's a problem that needs solving so we actually own and control our property.
EDIT: Do you often downvote people just because you disagree with them? You said it yourself you haven't given it much thought and your reply adds nothing at all. If any reply should be downvoted, it's yours. Have a nice day.
I didn't downvote either of your comments. In fact I'm not able to downvote your second comment (which frankly I think does deserve downvoting), I think because it's a reply to mine.
I hope you also have a nice day.
The statement you mention is a quote, and a relevant one at that.
But let's be clear - there is no way in which a "killswitch" requires "unfettered access to our mobile phones." Indeed, the UK (and I believe the wider EU?) has a global register of blocked IMEI numbers to which mobile phones are added - while it's possible to circumvent this in various ways, there are also more steps that could be taken to achieve the required outcome without handing over the keys.
Or if you want to push it a bit further, it's not hard to design a system in which an owner can cryptographically prevent the use of their phone without handing the keys over to a third party. However, the struggle here is that users would not engage with this system well, rendering it pretty useless.
So. Being wrong, being wrong, meta noise, bad attitude. Any questions?