We get back to the fact that even the 737 airframe is to big and a business jet would be more suitable.
It's not as dramatic as it used to be, but if you're going to fly it a lot (1,000 hrs./year) most bus jets cost more/hr. to operate than a 737. That's one thing that has really boosted the 737 BBJ.
The problem with distributed sensors/processing is it has to be 100% jam proof - and needs to stay that way indefinitely. If it's 99% jam proof you can be sure the 1% will happen at the worst possible time.