I actually think that either case(win or lose) have a lot of benefits for the government. If they win, they have the precedent and legal access ,so it makes their lives easier.
If they lose and the media circus leads people to strongly believe that the iPhone is 100% secure while it really isn't - gaining the trust that was lost due to snowden - this is really useful both from surveillance point-of-view , from blocking access to foreign countries, and for helping the iPhone usage grow, especially among "important" users ,be they legal or illegal.
But just looking at what seems more valuable for the government ,it seems that the second option is far more valuable. So i wonder ,why do everybody automatically accept the first motive ?