I'm sorry, I really should let it go, but...
Terminator 2 was not empty. Aliens was not completely empty. The Abyss was classic start shooting before you have a script debacle. True Lies was just plain offensive. (Those movies are fundamentally about Fatherhood, Motherhood, Marriage, and Cameron not realizing that he's a dick, respectively.)
The LotR movies, including The Hobbit, all made my ass hurt. Here's a good rule of thumb: movies should not take as long to watch as it takes to read the book.
It's the budget (which you allude to above) which is the problem. For a given film-maker, pretty much the bigger the budget, the worse the movie. Peter Jackson made Meet the Feebles, for goodness, sake. When he had to scrape by, he made amazing things. Cameron and Lucas have basically the same problem.
In your comment above you say Lucas only directed one good film. This is wrong, because you've forgotten THX 1138 and American Graffiti -- neither as good as the first star wars movie, but neither as bad as anything he did after that.