The thing is, hardware is key here. The OS matters, and I would bet that someone could do way better than running Linux in a watch (something much more low-level on a much weaker processor could extend the battery life significantly). The hardware and sensors is the big problem. Currently, the best smartwatch specs I have seen are the Basis B1. It claims it can monitor your heart rate, track your sleep, etc. But that…
Personally I'm excited about this and I hate being interrupted, but as will all things, with a little care you can filter out things you don't want.
> OS matters, and I would bet that someone could do way better than running Linux in a watch
There's tremendous value inherent in using a mainstream operating system, while the disadvantages are only short-term. Using a half-assed operating system widens the gap between idea to implementation and this friendliness to exploration and being general purpose is what makes smartphones these days great.