Drop "mobile" and I'm with you
Apple, since the iPod, I would argue, has been less in the business of "computers" or "laptops" or "mp3 players" or "phones" or "tablets" and more just in the business of making devices that people want. When you take the labels away, their strategies, which very frequently involve combining features of one or more of these classes of devices to create entirely new paradigms, make them money by creating classes rather than persisting in them.
Will Apple make anything that can fairly be called a "PC" ten years from now? I think so. Twenty? Dubious, but then, it might be that the PC will be totally dead by the end of the 2020s, so who knows. But, if Apple keeps doing what it does, what will be important about an Apple product of the 2030s won't be whether it's a computer or tablet or whatever. What will be important is that it will be cool and useful and that people will want it.
And this isn't limited to just mobile devices. Consider the increasingly likely Apple television set. Nothing mobile about that. But if Apple can come up with a workable concept for a giant screen that sits in the middle of your living room and serves as a seamlessly integrated media buying, accessing, and watching machine, I bet they'll do it. Call it a TV. Call it something else. Doesn't matter. It's a device. But it's definitely not mobile.
Apple doesn't make mere computers. That's why they changed the name. They make devices. Computers are a kind of device, to be sure. But just one kind. Maybe a nearly extinct kind. But you can bet Apple would never be so foolish as to say "we are ONLY a MOBILE device company." That would be dim.