I think the fundamental premise is actually wrong. It often is not better to have a compromise device than specific devices. Can you get along with a compromise device? Sure, sometimes. But the difference between no compromise devices can be surprisingly large in my opinion.

Most people I know haven't given up having a saw and a screwdriver and a pair of pliers just because they can buy a multitool that "does" all of that.

I also feel that a tablet has far more in common with an ebook reader or a smartphone than with a computer. I've yet to see a tablet do a task that a smartphone can't do, and I have to wonder if the "phablet" (god do I hate that term) won't be the convergence you're looking for rather than a convergence with a laptop.

I have yet to talk to a laptop user who wants to trade it in on something that isn't a general purpose computer.