> Who still wears a watch?
I do. (I'm young, too.) It's nice to be able to tell time by glancing at your wrist rather than fishing through your pockets for your cell phone. Especially if you're at a meeting that's dragging on—you can surreptitiously glance at a watch without being rude; it's significantly more obvious when you pull out your cell phone.
>have to charge daily
I don't sleep with my watch; I imagine most people don't. I'd honestly much prefer a watch that I throw on a charging stand each night. Finding a damn screwdriver that's the right size and hunting down the correct watch battery (if only they'd all just take CR2032s...) is a huge pain, even if it's only once every few months.
Maybe you're right that they're not watches in the traditional sense. But might as well capitalize on the customer familiarity. It is a device on your wrist that tells time.