[_broody]

> battery life that would probably outlast 3-4 iPhones.

And functional life as well. iOS 8 crippled A5 devices which had previously chugging along quite decently. Planned obsolescence sucks (in iDevices' case, it also affects present performance, i.e. Safari constantly having to reload tabs because the device has little RAM to spare). Unlike a smartphone, a simpler device won't be reduced to be unable to perform its more basic functionality decently a few years down the road...

[mynameisvlad]

You don't have to upgrade to iOS 8. Similarly, the 8210 wouldn't have had software upgrades, which naturally would be geared towards newer devices and cause the device to also slow down.

[acdha]

Security confounds that strategy unless you're planning to stop using data once an exploit is discovered which won't be patched on the old OS, which in this case happened the day iOS 8 shipped.

[_broody]

Upgrading is compulsory for many apps, such as Whatsapp.