Don't mean to start an Android versus iOS war here but I've updated the OS on several Android devices several times. And Apple could learn something from that process.
Rather than simply tossing open the doors and inviting a stampede, manufacturers or carriers typically stage updates for large but manageable groups of users over a period of a couple of weeks. Had that been done in this case there would have been the usual grousing about waiting in line for one's turn but the fiasco that continues tonight would have been avoided.