OK — Color me clueless, but I simply do not understand the government’s position. They simply do not appear to know what it takes to decrypt an iPhone, so they are taking the easy way out. Make someone else do it.
1. If you have too many failed attempts, using the iPhone to access the data, the phone will erase the disk. So, trying different passwords is not an option.
2. The first thing you do in a case like this is make a copy of the raw data to protect against option one.
Back when I worked at a chip design company, I read a lot of papers about the tools they were using. If I was one the government team, the only thing I would want from Apple would be the specifications for the hardware and software. (most of which is available from the patent office)
I would then contact the chip manufacturer to get information on mirroring the data to my supercomputers. Once the data is copied, the rest is a matter of time. Apple can’t do that, but there are government sponsored research centers that can.
Apple sells its products to countries in Europe that still believe in civil rights and privacy. The day they put a backdoor into their products is the day they become illegal in those countries and the day people like me would start migrating away from their stuff. (Which I use almost exclusively.)