Great points throughout. Interestingly, James Patterson, at least in my opinion, is barely literate, but he's the best selling author in the U.S., I believe.
I see two reasons for his success:
1) He tells a pretty good yarn, even if reading him makes me feel like a sixth grader.
2) He's a master manipulator of the process. Good for him, I say, for figuring out the formula. It's not his fault that the publishing industry is in the rut it is in.
My favorite trick of Patterson's is getting his friends on board one of his novels. He'll give someone a byline, and usually one chapter or so in the book. Sometimes that chapter is so unreadable you want to throw the book at the nearest Republican. (if you must throw a book at a Republican, aim for the mouth to keep them quiet for a day, and make sure it's a sturdy hardcover)*.
That of course raises the question, "gosh, how many of Patterson's books have you read that you know this?"
Well, maybe about three is all (they all had "co-authors"). But they take about a half hour to read, so if it was 50, I wouldn't feel particularly guilty.
* DISCLAIMER: This comment in no way endorses or condones violence of any kind, and any interpretation otherwise is a reflection of the reader's inability to appreciate bad, dark humor.