Oh, so the square shape is for the youngsters and the round ones are for the elders ? Funny how the history repeats itself. How about your "elders" who used to wear these square touch screen watches in 1984 - so 30 years ago ?
Stretching even further back, you'd be hard pressed to find a round wristwatch from sometime in the mid-1920s to the 1940s and even on up to the 1950s. The '50s even gave us a triangular watch
Round wristwatches really didn't become popular(again) until the 1960s.