It's good to look at the water in the glass, even when it's not even half full. I guess.
The iphone made computing ultra portable, the iPad reinvented the couch, and both of them revolutionized the toilet experience.
The iWatch doesn't quite revolutionize or transform anything. There is no inherent advantage to having half-a-computer on your wrist at all times.
The iWatch is a fashion item at the moment - hackers don't seem to be impressed with it as much (judging by the very few articles about iWatch on HN :)). And if you don't impress the hackers, your days are numbered.