Yes, yes, that's all very clever of you, except for the fact that iPhones do have that. You can reset the firmware, or all the internal storage, from a plugged-in computer. Almost every single byte of internal flash can be rewritten by Apple, or, hell, by an end user with iTunes. (I think the only parts that can't be overwritten are the parts that allow the phone to enter recovery.)
These 'bricked' phones? They enter recovery mode just fine, and all their internal memory can be rewritten just fine. Everything works fine there.
The problem here is that the current time, of course, is not part of a system recovery, because the damn current time is not saved to the phone's flash memory. How would that even work?
The clock in an iPhone operates the same way the clock in a PC operates, in a separate very low-power clock-tracking chip that runs off a battery. (Which in this case is the device battery.) There is absolutely no way to alter this from outside the device, and, really, no device has even needed such an ability before. iOS just has a really stupid bug.
And the way the iPhone is designed does not allow easy removal of the battery, which, really, is the problem here. If Android had this problem, it would be laughed off, 'Just unplug the battery, that will fix it'. But you can't do that with an iPhone.
I suspect that, within days, Apple will have produced a iOS update that can be put on the device (Even after it has been 'bricked'.) that either checks the time and fixes it, or just doesn't have whatever bug is causing this in the first place. (In fact, it should be possible to put a tiny image on there whose sole purpose is to change the clock, and then put the *original* image back.)