I Think I Don't Want These Computers in Cars Anymore

Yeah so 400k is 2 design lifes for a car, so regardless of if its lit up (Sensors can be replaced and they usually aren't too bad), the car still works. Testimate to the design of the car.

Electrical systems on anything TIPM days or newer at Chrysler can be a nightmare as they are generally riddled with faults so that doesn't shock me.

Usually they flash a message up and then you can hit whatever the equivalent of set/clear and it would show you the normal screen. I have only seen the TPMS failure in a GM car. From a practical standpoint 99% of people don't have any way to get the TPMS sensor out of the tire on their own, so they take it to someone with a tire machine and they wing a new sensor in it, re-inflate the tire and send you on your way. Taking it apart to change the battery (some are overmoulded anyway) probably isn't worth the labor to parts savings. Shops are probably paying $12-15 for the parts for that which in a lot of places is ~10 min of labor.