Ok, I wear a watch. I wear a watch for many reasons, the most obvious one is so I know what the time is. I happen to like my watch, it's a simple classic design (was going to say timeless piece, but then I'd probably have to shoot myself), it's a gents watch, it's a little on the large side and I like that. Never, have I associated wearing a watch with age.
I have a mobile phone, which also doubles as time piece, camera and general tracking device. This, is implied by that statement I guess: you don't need a watch because you have a mobile. Nope, not buying it, checking the time on my watch (on my wrist) is far more convenient than fumbling about to liberate my mobile from my bag, then, I'd more than likely have to charge the bastard, and, to do that I'd have to first locate the charger.
Wristwatch has a ring to it that wristphone will never have (excuse pun).