Isn't this kind of a double speak straw man argument? You are insinuating that the masses are not knowledgeable enough to know when they should update, not knowledgeable enough to make informed decisions, yet apple owes them a responsibility to be able to downgrade. If they are not informed enough to handle one click upgrades, then how are they supposed to be able to handle the technical parts of a downgrade? For this to happen apple would need to create the same no brained one click downgrade, so thus requiring more support and testing on their part. If you can't trust apple with the upgrade how can you expect to trust them with the same downgrade.
Maybe the answer is to go back to non-upgrade able (or non-user upgrade able) devices so that the user will be perpetually available to the originally supplied OS.
There are some really helpful people in Apple Stores, that would be able to downgrade your software if they could. I'm not saying my argument is perfect, simply that it is valid. Apple is marketing to the masses. They want everyone to use their iOS devices. They cannot expect them all to sign on and read tech websites to know about flaws in iOS updates.
I updated my phone. I'm okay with the update, though I think it still needs a lot of work, and that UI unification should be a priority. My wife though, isn't as content with the update. I should have made her use my phone for a few days first, before updating her. I wasn't aware of the one way upgrade when I did it, even though I tend to follow tech news.