I'm sure that you are right that the movie drew a huge audience, many (if not most) were folks who had read the books. Perfectly understandable...I had read all of James Ellroy's books, so I was drawn to "LA Confidential" and "The Black Dahlia". "LA Confidential" was, IMO, pretty good, although it deviated from the book quite a bit, and having just read the book I was confused at points because I knew what was supposed to happen, and it was changed in the movie. I thought "The Black Dahlia" was not successful...
Josh Hartnet was pretty poor, and the script was weak.
Apparently the first "Hunger Games" not only didn't tank (my opinion notwithstanding!
), but made a fortune. I'm sure if they make a sequel it, too, will do great...even if it's as bad as the first one.
Once again, my evaluation of the film is mine own...and clearly in the vast minority!