I think the 'health' market is a bit more fragmented and complex than that. Simplicity is simply not the only driver at work in this market. There are sub-markets that are interested in tracking more than just their daily step count.
Even a back marker triathlete wants a watch like a Garmin Fenix 3 or 920XT that can track their open water swim, time spent in transition 1, link to their power meter on the bike, time spent in transition 2, and their run.
And, of course, link to and upload their split times to Strava and Garmin Connect.
This crowd will gladly dump their current watch once the next gen figures out how to add more complexity and include a power meter for running!