My mom's iPad is my old short-lived iPad 3. She gets Pinterest, she browses the web, she does her email, we Facetime. My dad borrows it from time to time to buy a rare book online or to look for some obscure Prog Rock band from the '70. He is the typical proudly tech-illiterate son of the fifties, but well, he actually loves to use his iPad 1 as a YouTube Radio when he's painting.
She has a laptop at home, but it's strictly connected to work related task. I.e. spreadsheets. And that's it. Her laptop and her iPad are perfectly complementary devices she is not really thinking about changing until they will break or become unbearably slow.
There's no mystery: the iPad IS a computer, and its update cycle reflects it.