Anecdotally, I've found that "non-technical users" have trouble adjusting to any new UI, including Apple laptops, phones and tablets.
For them the choice is between keeping an old computer, on which they already know how to send emails and compose documents, and buying a new tablet on which they will need to learn a whole new set of UI idioms. In addition, physical keyboards and larger screens (and no "ipad neck") make laptops and desktop computers more attractive.
Add Windows 8 to that, and oh boy, there's a lot of tears. My aunt's laptop died so I bought her a new one. Every time I talk to her she's complaining about the Windows 8 UI. She still hasn't figured out how to do some tasks she would do before with Windows Vista (which she had no problem with).
For them the choice is between keeping an old computer, on which they already know how to send emails and compose documents, and buying a new tablet on which they will need to learn a whole new set of UI idioms. In addition, physical keyboards and larger screens (and no "ipad neck") make laptops and desktop computers more attractive.