"Computers" still get viruses, require backups done by the user to be safe from data loss, have out-of-date software packages (each with its own broken update mechanism), take ages to boot up, are clunky and slow...the list goes on.

Sure, none of those are specific to the "computer" form factor. But they are all things that people think of when they think about their desktop computer (some mac and linux users excluded, of course: but that's still only 10% of the computer-using population). NONE of those items I just listed are problems with any "Tablet" computer.

The form factor is different, but so is the very model of user software and computing.