cheapest option wins
There's not really 20 watches though are there... there's one... which comes in two sizes (38/42mm), and with a case made of Aluminium, Steel or Ceramic, and then for any of those a range of strap options.
Sure, if you multiple out the possibilities, and call that the watch, there's a lot, but the reality is it's one watch with a few options.
My view is less about apple attracting people about wanting a sport watch, but two other factors. Firstly the high price, regardless of which materials you choose, it's expensive, and second by pricing differently per strap choice, making the cost of the strap almost entirely transparent.
So for example when I bought my V2, I saw that a steel strap costs £150... I figured I didn't want to spend a) that much in total and b) certainly not £150 for a steel strap... and so bought the cheapest option, the sports band.
As such I expect many buying the "sport" options are doing so as they're the cheapest.