I think it's mostly the American tendency to inflate controversy, and it's particularly juicy given that Toyota is the biggest car company and the Camry is now basically the All-American Car. Of course, it seems to me that all the controversy is warranted: I subscribe to the theory that the problem is with the software that controls the engine and transmission.
This is because of my own experience with a Camry that shifts at the wrong times and has unpredictable acceleration or lack of acceleration. Several months after we bought the car (a 2007) we were able to get a firmware upgrade that improved the performance somewhat, but at the cost of gas mileage. Since the car doesn't perform as well as it should (it's nowhere near as responsive or efficient as our '97 Camry was), it seems like the underlying problems still haven't been fixed.
Toyota has offered two other "solutions" for their problems, but neither rings true, and as the LA Times points out, neither can explain all the reported incidents. If Toyota were covering up their inability to find and fix the real problem, this is what it would look like. Here in the US, we've seen a lack of honesty from Toyota that seems very typical of American corporations.