Yes, they actually save a significant sum with touch screens. Not only are the components cheaper (1 ~$150 touchscreen is cheaper than 15x $2 buttons w/ associated hardware + 10x $10 dials w/ associated hardware), but the wiring and electronics get significantly reduced.
Plus, people liked the idea of touchscreens before they found about the actual downsides of touchscreens. So they were both meeting demand and doing cost savings at the same time.