I wish my iPad 2 could go back to iOS 6. They literally destroyed the device forcing us to move to iOS 7 without the ability to go back. Biggest mistake I ever made was upgrading the iPad 2. Now it is a slow mess of crashes.
I know that many will harrumph about how poor little Apple is the target of frivolous lawsuits but as we've seen time and time again, Apple is so big that they are reluctant to respond to customer complaints until a lawsuit is filed (or a serious threat of one being filed).
One possible good thing that could come from a lawsuit like this is Apple providing a way for customers to be able to downgrade to a previous version of iOS for their devices. Highly doubtful that Apple will do this, because to do so would potentially make 10's millions of iOS devices functional again (or far more usable than their current state).
Yeah, I know there will be those in response who will trot out those well-worn strawmen:
(A) developers will be unable to provide support for their apps on multiple versions of iOS. Answer: Nothing needs to change. Whatever the latest version of the app was supported on that particular version of iOS would continue to be available "as-is".
(B) fragmentation. (related to "A") There is already fragmentation since not all devices that are capable of upgrading have upgraded, and not all devices are capable/allowed to upgrade.
(C) security. By allowing devices to downgrade, Apple would be allowing customers to expose themselves to security flaws in those previous versions of iOS. Again, there are still devices running older versions of iOS (out of choice or necessity).
(D) Customer complaints of reduced functionality. People will complain that they downgraded to a previous version of iOS and are now unable to use the latest version of their apps. The answer for those people: upgrade.
Downgrading iOS wouldn't necessarily need to be a highly visible option where the uninitiated customer might easily stumble upon. Apple could make it "as-is" just to make it clear... not that there would be many devices that could downgrade that would still be covered by warranty.
The last time customers made a lot of noise, a LOT of noise, was regarding Apple automatically downloading the iOS updater/installer to devices whenever a new version was available. One could not prevent the updater from downloading. There were ways to temporarily delete the installer but it would eventually reappear. Defenders of Apple claimed that it would be too difficult, cause too many issues, and cause confusion for customers. But Apple DID respond to that and it was in iOS 8 that they provided an option that would prevent the installer from downloading.
Apple does listen, but sometimes not so willingly.