I think that it will sell well but, as you say, people on places liked DressedWell and SF aren't Apple's target customers for a smartwatch.
I'm sure that there are lots of people who will be willing to buy the more basic versions because, after all, they're cheaper than a phone and there are millions of people who are happy to buy new phones and tablet computers every few years, so I don't see why smartwatches will be anything different.
Personally, I've outgrown the desire to imitate Dick Tracy and I don't feel the need to obsessively monitor my messages/e-mails/health alerts and so on, so I shan't be getting an iWatch.