Farhit: In your case, I can see this makes perfect sense. You clearly must be watching a "dashboard" of indicators all the time, and the watch will enhance your productivity. There are certainly other professions where this would apply -- nurses who have to watch many patients, police who need to monitor numerous situations, engineers in a utility plant, etc.
But I sense the vast majority of people buying these devices are ordinary consumers who want to have a constant connection to their smartphones in a nonprofessional context -- people who live from Tweet to Tweet and deparately crave the approval of the crowd. I just feel sad for those people.
If my friends really want to reach me at any time, they know how. I don't feel a need to check constantly to see what they posted, and I would hate to think they're waiting endlessly for me to post a new photo of my dog.