You're absolutely right. Next time someone says DST exists "because farmers", point out that they don't milk cows and hour earlier or later based on the clock on the wall.

Also, in seasonal "touristy" towns, lots of shops have seasonal hours. We don't need to muck around with the clocks on the walls (and all the devices with internal clocks) for everyone because we want to start school or office hours earlier or later. Just have seasonal hours for businesses that care.