Not only are the iPhone, iPad and Watch computers, but they are all massively more powerful and capable computing devices than many of the Mac's that I've owned. An iPhone 6 is not only more than a thousand times faster than a Mac Plus, but can do heavy number crunching faster than a Cray 1.
It's the direction that the computer industry is heading. Mainframes and minicomputers are no longer the most common computer that most people see or use anymore (as they once were). The same has already happened to desktop PCs, and is now happening to traditional looking laptops. Apple is leading that wave.
Software and chip design are the key components of being a computer company these days, and it appears that Apple is still a leading, if not the leading developer of consumer-facing software, sharing tons of technologies between OS X and iOS, as well as giving Intel and AMD competition in the space for low-power computer chips.
So, yes, it's still their core business.