Why was the software not such a big problem with other jets like F-16 and F-22? Is the F-35 software really so much more complicated?
2) The F-22 software was largely written in Ada, a sane language that's great for real-time systems that cannot fail. Apparently the F-35 software is mostly written in... C++. Writing fault-tolerant real-time C++ is like walking on a tightrope while gripping a gun with the safety off. You can do it, but it's not particularly pleasant.
3) Apparently the team was considerably expanded/replaced between the F-22 and F-35.
What the heck are we doing with these airplane projects? We build stuff we don't need, that doesn't work, and is waaay more expensive than we thought, and the starting cost point was extremely expensive to begin with.
It was canceled because it was expensive and no longer needed, because the mission it was designed for - fighting a peer enemy - no longer existed. That was 2009, when the U.S.'s primary military concern was fighting two simultaneous wars against enemies who didn't own one airplane or air defense system. Any plane could do the job; we didn't need F-22s. Also, our prior generation planes were still the best in the world.
Seven years later, Russia and China have engaged in massive military military buildups, including significantly improving their air combat capabilties, and aggressive behavior. The peer enemy mission is back at the top of the list (and some are now talking about re-starting F-22 production).
Gates is also on record as saying that the F-22 was cancelled on a cost per aircraft basis. Which is a bit of a circular argument, because the cost per aircraft would dramatically decrease if the originally planned number had been built.