The idea of "the death of the PC" is just that - it's an idea. It's a hook that, if you believe in it (and I do), it can be quite informative about what seems to be happening to the PC industry, and the wider computer industry in which it sits.
I don't think the PC is dying in a literal sense. The PC is stonkingly good at the things that it does well. But I'm a technologist - I've been using PCs since I was twelve years old and I like the power and flexibility. Like most technologists, the PC bends to my will like I have a superpower.