One, adding hardware to connect to WiFi and cellular increases size and power requirements. Notably, the new Pebble 's battery is projected to last 30 days.
Two, people use phones. They want their watch to work with their phone instead of around it.
WiFi and Cellular are avialble on the smallest of apple watches. I don't care if my smartwatch can go 30 days between a charge, none of that matters if it can't do what I want it to do. I had a pebble back in the day and I thought it was useless as it was such a limited device and it sounds like they want to replicate that experience. I'm happy the people that want such a device are getting it, but I don't get the appeal and want a device that can do thing.
