I wonder if that was the case with earlier cars? Yet today lots of people drive who aren't 'grease monkey's.' While the knowledge & skill to handle problems is good, it's not always present or practical.
It's kind of like learning to fly a plane in case the pilot & copilot ever both drop dead of a heart attack, and you're a passenger.
I'd like to see rebreathers get that idiot-proof. But I think that's a long way off.
Richard.
I think the car analogy is right. Mustard Dave is dead on IMO. Diving a rebreather is half the fun of having a rebreather. A rebreather as automated as you suggest would be like owning a Ferrari that didn't have a driver seat and made you ride bitch.