Design vs Functionality

An interesting view.  With the obvious example of smartphones converging on a rectangular design.     " ... In a pre-iPhone age, mobile phones came in all shapes and sizes. Remember the clamshell, candy bar, swivel, backflip, slider, dual-slider, lipstick, and, of course, the taco? Nowadays, most phones have a touch screen, rows of icons and are rectangular. ... " .  So does strong consumer accepted design trump functionality?