The thing that makes this a story isn't that something can be stolen. ANYTHING can be stolen.
The thing that makes it a story is that Apple Watches, at the moment, are fairly rare. And, as smart watches go, they are expensive.
That makes them more of a theft target than a Pebble or what have you.
Over time, this will be less of an issue as the Apple Watch becomes more commonplace. And, let's face it, they'll have to sort out some way to discourage theft.
All this aside, I'm kind of glad nobody seems to recognize my Apple Watch when I go out and about. And I live in an affluent suburb, so people here can surely afford them, so they're the target market.
I think that, for now, the general public just aren't used to seeing them, so they may be less of a theft target. As their popularity increases, the odds of theft will increase (just like it did with the iPhone).