This is a classic case of learning nothing by averaging together two different populations (as acknowledged in the article, critically-acclaimed indies and mainstream blockbusters).  Its like averaging the height of an NBA team with a kindergarten class.  It would probably be more informative to group movies by size of release (number of theaters they open in), as well as advertising budget.  Just by eye there seems to be a correlation for well reviewed blockbusters to do better than poorly reviewed ones.