It's worse than that actually. The newer Tesla's actually include a "beta feature" to guess which way you want to go. The idea is you should never have to use the touchscreen: When you put your foot on the brake the car automatically selects F or R based on what the sensors see. Like in a parking lot if you parked nose in, it would see another car or wall in front of you, so it would assume you want to go in reverse.

It's labeled beta and disabled by default, but lots of Tesla features are labeled beta and still get used a ton.