It's not a bad idea but it would be very complicated to implement. You also wouldn't be able to see the correct end result in the preview which would be an annoyance. Lastly, I believe it's pretty niche. Some user would LOVE this functionality but they're pretty few.
Firstly because you already have excellent post process control if you take a RAW picture and secondly because you need a lot of time doing these changes. So photos of anything that has a mind of their own, will get tired waiting for you when you try to find the perfect setting.
