We'll have to agree to disagree. 1) I haven't heard the apple watch discussed at all outside of the techosphere. It's a test-pattern. Nobody I've met wants one. The Hodinkee blog is from when the watch was brand spanking new - it's essentially speculation. There's no real world test as of yet. 2) It's also possible that Square didn't dominate for the same reason Nike plus didn't dominate: there isn't that much need for the product. My wife's been using a Square for three or four years now and it only comes up rarely. She also takes checks, cash and paypal. 3) Regardless of whether or not Square "sucks", the investment cost to get into it is zero. They charge you $10 at Kinko's and refund you $11. They ship new ones at random - we've got three of them sitting around the house. And they'll take a Centurion card so it's not like they're inadequate. You've listed reasons they could succeed, not reasons they will succeed. I guess we'll just have to wait and see.
For sure, I don't want to be too far on the side of saying it will be a hit...I'm just saying I could see it. Much more than any other wearable so far. But ultimately, do you really need what wearables can do for you atm? Meh. Regarding Square, yeah, I think so. Their market just isn't that massive. What does your wife do? I don't see too many people taking checks. My wife doesn't even take them in her store (exceptions for customers she knows well).