1. It was the time of "One Windows". It didn't run Windows, and Windows wasn't going to ready to run on a wearable anytime soon.
2. It was expensive to manufacture. Curved screen, curved batteries, 2 rigid bodies. Everything about the industrial design was completely custom. It was amazing we even pulled it off at all.
3. Microsoft is afraid of entering new HW territories, HW tends to lose a lot of money.
4. Windows Phone died, which shouldn't have had an impact but it kinda did mentally. Users were actually evenly split between all three platforms, (which means Windows Phone users loved us!)
5. No one was willing to put in the actual engineering effort needed to do it properly. The entire team was burning out and we were bleeding people. Consumer hardware is not supposed to be at a 1 year cadence with only 1 team doing everything. Doing it that way also means you don't get a chance to make any dramatic changes, we had to only make small iterative improvements because if you only have 8-10 months to get boards up and running, get software ported over, and then finalize everything, well, you are working insane hours just pulling that off.
As a user it changed my life. I will never not wear them (on the Versa 2 now), and have years of actionable health data that has been life changing. And it's still so obvious to me that this is still the very, very early days of wearables and consumer biotech.
I was heartbroken when it was discontinued. I would love to read the high-level strategic thinking behind that. I understand perhaps the thought was Apple Watch would be tough to compete against, but the Band was years ahead of Apple (the first couple generations of Apple Watch completely missed the key point that the killer app for watches is health) so I like to think it had a chance, but more importantly I thought it was a fight worth fighting because of how much impact these things will have on people's health. It was also just inspiring that a new product like that could come out of Microsoft, and sad to see they didn't give it the 10+ years it deserved.