To a degree, I completely agree with you. So, we, you and I are probably avid divers, but we are less then 5% of the divers in the world. Many people do not want to have to purchase a new item for everything they do. Again, increasing market share making making your Watch more viable. Looking at the Garmin App store, it was a lot of option to make the Garmin a more everyday every activity watch. The Garmin also can check certain vitals while you are diving. My HS electronics died of a heart attack in 1985 while diving in Long Beach Bay in 1985. Could a Garmin given him a heads up? I have no idea, but it is a thought and a direction for the future.
My local LDS has owned his shop since the 1970's, and thousands of dives. He sells both Shearwater and Garmin, when an older 68yo man raves about a Tech product for diving, I try to listen. He is not selling me one, as he sold me my Teric and Perdix AI, but he just loves the Garmin.
For the record, I love to be a Shearwater Reseller, but they only allow brick and mortar shops.