The issue with saying "Oh yeah the Apple Watch is killer for fitness!" is that everyone who is into fitness and who cares about tracking stuff already has a fitness tracker. And these fitness trackers are cheaper, smaller, hardier, less of a target for theft, don't need to be continuously paired with a phone, and don't interrupt a workout to notify of text or phone call.

Nobody's going to jump me on my morning run to steal my FitBit, but they damn well are gonna jump me for my Apple Watch. I'm not going to wear my Apple Watch doing something like Crossfit where it could easily get broken but I'll happily wear my Jawbone UP because I know it can handle it. Also, fitness wearables are simply more comfortable to wear while exercising compared to the Apple Watch because the watch is bigger with a much bigger band and watchface for sweat to get trapped behind plus it has to be worn tight to the skin to capture heart rate which greatly limits range of motion.