Let me just chime in here as a customer. I have a P-ROC running on my Demolition Man, and the opportunities that the P-ROC presents are far from limited. The fact of the matter is that P-ROC and its associated software kits are frameworks. This is probably the best model that I can think of because it leaves the game rules and behaviors up to the designer (you). With that said, these frameworks take care of a lot of the "nitty gritty" stuff such as switch handlers, ball trough logic, etc. In an open environment such as a pinball machine where your inputs are manipulated randomly, you have to leave any assumptions about what you're going to have to deal with at the door. This is the reason that developing a simple "hands off" framework such as a WYSIWYG is quite hard to do successfully.
The pinball machines you're used to were pretty much written in assembly. Even for the "modern day" software engineer, this can be difficult since creativity is easily stifled because you're having to worry about bit-level logic.
With the P-ROC, you have the entire toolchain already laid out for you. You have utilities to convert graphics into DMD-ready images, you have a sound manager, a mode queue and lots of sample code to go on. Also, the Python language (if you decide to go that route) can run on virtually any platform. I've also run this on the raspberry pi and TAF.
There is a customer base that has proven that you don't have to be a software engineer to get a game flipping in minutes. For those of you who have seen the Cactus Canyon Continued project, all of that development was done by a single person who isn't a software engineer, and its his first time ever looking at the Python programming language.
Coming from a background that has required me to do both assembly and higher level python coding, I'd take this framework any day over assembly, an arduino and shift logic, or any other alternative I've seen come to market.
Regarding the JD code, the code wasn't marketed as a drop in replacement for your existing JD software, it was designed to show the aspiring pinball programmer (and the potential customer) what could be done with the P-ROC and the entire toolchain that surrounds it. The framework has been extended considerably over the last three years since that code has been written as well.
Once again, just my two cents as a customer!
Happy flipping!