Again I go back to complex made made devices like aircraft , years ago when I worked on Hornet fighter aircraft , the complexity and software issues and maintenance with that aircraft we huge , when it was brand new, it settled down after few years, but that took a decade,
So you had some field service bulletins, procedural changes, and other things are are awfully similar to a vehicle Recall?
Complex systems, including software, become practically impossible to reduce to an FSM. There is a very large component of software to the Cherokee and all new/high-tech vehicles.
Even with NASA-level software scrutiny and avoiding the bleeding-edge, "stuff" still happens. And, as long as consumers want the latest, greatest, shiniest thing, and the EPA keeps pushing down CAFE, there is going to be more priority to getting something out to market than getting it out at 100%.
My 1976 Chevy truck was very reliable in 1996. It was also very easy to diagnose and repair. It was also extremely uncomforable, and the only "luxury" it had was cruise-control and AC. I've chosen I want comfort and convenience over pain and reliability.