I guess it really depends on how you define "support". I certainly DO expect Apple to support their iPhones for 5 years or longer since again, they control the hardware, software, integration, OS, and apps that get installed on it. These items are $1000 each (basically) and are really just a computer with the ability to make a phone call than actually a "phone". Heck, the phone features haven't been updated since the iPhone 1.0. Seriously.
I expect Apple not to force me to upgrade to a new iOS and get alllllll that baggage that was never designed for my 1-3 year old phone...new looks/feels, icons moved all over the place, new bugs (of course), apps removed, etc. Now technically nobody is holding a gun to my head to upgrade, but I very likely have to upgrade to get a new version of my non-Apple apps. I also am not a fan of the contstant trickery in that Apple pops up an alert about a new iOS version and I CANNOT decline it...I can either accept/install it or I can choose to have the alert pop up some other time in the near future and nag and try to get me again.
If Apple is going to pop up alerts while I am using my phone, trying to get me to upgrade iOS, then Apple damn well better have a much better "support" track than how Apple operates now.
If Apple allowed me to back up my phone, upgrade to a new iOS, and then rollback to the OLD iOS/backup if I don't like said new iOS, sure, that would be ok with me. But no...once you go up a level in iOS, you can never, ever, go back an older iOS. That is just pure evil. It's also quite opposite of a "backup."