I think that Apple Watch owners are not the only people Apple is targeting with the icon. I’ve always believed that it is also some sort of marketing campaign that reminds you time and time again that you are incomplete without the Apple Watch. It could easily be a downloadable app, otherwise.
I definitely agree with you that the current icon is looking far from great, but even people who haven’t seen the Apple Watch, recognise it.
I do think it’s a great read though. I really like the process you went trough and I would definitely prefer this icon over the Watch icon that we have now. Ideally I wouldn’t want to see the app at all, but that’s another story.