It doesn't help that "upgrading" an iOS device is a one-way ticket.
Religiously updating the original iPad effectively bricked it (not literally, but to all intents and purposes) years ahead of its natural lifetime, due to one particular major release that killed performance, reliability and battery life in one fell swoop.
If there no going back, why would you risk going forward?
My iPad 2 is still actively in use on iOS7 (it was better on iOS6) and I was using iPhone 4S with iOS6 until the end of last year. Many other people reported bad degradation on iOS8/9.
Religiously updating the original iPad effectively bricked it (not literally, but to all intents and purposes) years ahead of its natural lifetime, due to one particular major release that killed performance, reliability and battery life in one fell swoop.
If there no going back, why would you risk going forward?