This is how I use my watch. Pretty much strictly for push notifications. I think people who thought the apps would lead the way are the ones who are most disappointed. I use notifications, the fitness app, and the hue app for my lights. I personally find all other apps to be pretty slow and a waste. The ESPN app is awful. In the time it takes to update, I could have looked at scores for every sport on my phone.
I am finding that people who came from a different smartwatch are loving it, and people who this is the first smartwatch are having buyers remorse.
I don't think it's quite that clear cut. I didn't own a "smart watch" before and didn't give it much thought before the Apple Watch. I did have a regular watch, though. I agree that those who wanted to use lots and lots of apps are likely the most disappointed, but seeing as we're talking about a 1.5" screen and don't even have native apps yet, I wasn't expecting much. The best apps will be those that do one or two things really well. Opening a hotel door instead of fumbling with a card key (that I tend to misplace) could be one example. Weather takes a while to load up at first, but after that it's fine. The watch face complications and notifications are the best parts.