That's a bug or a feature, depending on your perspective.
If you are thinking of it as a standalone watch, then obviously, it's broken. Lousy battery life, bulky, needs an iPhone to work ...
On the other hand, if you are used to carrying around an iPhone but are annoyed when it rings at inopportune times, and you have to take it out and check it, then, suddenly, the iWatch is a win!
It does what that Swiss relic did, only more accurately and without needing to be "set" (a quaint term having to do with calibration of a timepiece). And it lets you monitor most of the functions of your phone merely by looking at its face. Of course, it does need to be charged daily. But so does your phone (and you), more than likely. So, you just plug it in, alongside your phone, and that's that.
Depending on how many times that happens, it could be a very expensive win, and it's not saving you anything if you end up having to get the phone out anyway.