I would have to disagree with the logic here. Multiple upon multiple projects are underway, from integrating your car's O/S with blue-tooth, building systems, shopping options, etc to become Internet integrated. This wasn't the case 10 years ago, and comparing MS (who frankly is uneven at best) handling of the entertainment industry in the living room is simply not equivalent to the myriad of obvious applications coming (hell, just think of Medical) wear a wearable is quicker and more natural than even a smart phone. The better way to look at this if you want a comparison would be to compare the rapid emergence of the Cloud for general computing compared to the first attempt. Few now remember this "cloud" is nothing new; it's the re-branding and re-introduction of what some us recall at the end of the 90's as ASP's or Application Service Providers. The time wasn't right, it took another full decade to be realized once the Internet was sufficiently powerful enough to accommodate it but those technically aware enough of the big picture recognized it was the natural direction of things in time.
I believe we in the same position with wearables, only the time difference is say three years as opposed to about 12 with ASP/Cloud services. If you think it is about YouTube and the apps usage you are missing the point entirely of the integration possibilities which are all but inevitable. 90+% of the folks returning their Apple Watches will own another within five years, mark my word.
First of all cars already have bt.
Second RFID in grocery stores. Yes it will happen. But why do I need ApplePay in my bracelet or sunglasses when I already have it in my cell phone?
Third we've had watches that track heartbeat for years now too. While I admit being able to send that info to a central database and harvest the data may be useful for insurance companies or possibly some studies, I don't see it being big enough to start an entire wearable market. Furthermore a dedicated medical device would probably function better than a jack of all traits apple watch.
Perhaps the biggest issues with your viewpoint is that A) you haven't defined what wearables are and B) you haven't stated what problem they solve.
Wearable are bracelets, necklaces, sunglasses, pants, coats, and of course watches with embedded technology. But what problem do these devices solve? And more importantly is that solution greater than the additional layer of complexity and of upkeep (such as charging)?
I personally don't see it.
Would Steve have done this? Of course. Technology has become increasingly personal over the generations, and wearables are about as personal as we know how to get right now.
By this definition Apple invented the wearables market over 10 years ago with the iPod.