A few problems with that:
1. Understand that Jonny Ive and the movers and shakers at Apple probably get an order of magnitude more notifications than most people do. They are, after all, important people with lots of scheduling and lots of communication. My phone isn't ruining my life. I don't get a notification every few minutes.
2. Android Wear is a notification device. We've seen how people like Android Wear: they think, eh, it's okay. What is going to make Apple Watch different? The people I know with Android smartwatches aren't saying, "Oh, god, I almost love this but if only the watch were prettier," or "If only the UI were a little more polished." They're saying, "It's nice to be able to get notifications on my wrist, but it's not a life-changer and it isn't worth hundreds of dollars."
3. And part of the reason for #2 is that if you're really getting lots of meaningful notifications, you're going to want to act on some of them, and the watch form factor is just fundamentally bad for acting on anything.
As long as smartwatches are just notification devices, they're inessential peripherals that probably won't get truly popular until they're sub-$100.
If there is a killer app suited to the watch form factor, it hasn't made itself known yet, and it may not exist. Or it might exist and just be hard to find. I think there are surprisingly few really killer apps on the smartphone form factor -- the only one that I think genuinely fits the bill is Uber and its competitors.
EDIT: As several people have pointed out, the browser, messaging, navigation, and camera of the smartphones are definitely killer apps, and are what made the smartphones obviously useful from day one. I agree with that and just left that context out. My comments about Uber are more to do with "new things that you can only do on a smartphone that weren't there on day one, that are also genuinely useful." There are remarkably few apps like that on the smartphone. I think that smartwatches are in trouble because the stuff that's there on day one isn't very compelling (look at notifications), and evidence suggests that it's very hard to create all-new highly compelling apps that aren't obvious on day one.