That is a real problem. Phones are also subsidized in purchase by the carriers, at least in offering a credit system to spread the purchase out over time. Tablets of any kind must offer some really compelling reason for upgrading or they are not going to be upgraded. The iPad IS a very good product in almost all of its versions and keeps on trucking. Even if it breaks in a fall, it's easy and economical to repair rather than replace. Apple's superb design is it's curse.
I just spent an hour rehabbing some old iPads for kid use.
I think the marketing of iPads has been directed at the idea that you would upgrade frequently, when there really is no reason to.