You obviously have your mind made up and no amount of proof I present is going to make a difference. If it's so easy how come no film that I've seen has duplicated it. Which of his films are forgotten? Even something like 1941 has a cult following these days. The Color Purple was a serious film about the African American experience not a common or commercial venture 20 years ago. Your criticism seems to based more on script which I don't really care that much about. Movies aren't plays. You either apprieciate the formal propertries of filmmaking or you don't. On that basis I thought Titanic was a great film and Art every step of the way.
The only thing you've proven is that every turd Spielberg drops on the ground you'll find a way to call it art.
Actually most of his movies have been forgotten, he makes movies for the moment. Outside of his early years and Saving Private Ryan 5 years later people just don't care. That's why I compare him to top 40 music, it's all for the moment with no staying power.
Scripts are important, all the best film technique in the world in service of a crappy script makes a mediocre movie. I appreciate the formal properties of filmmaking, but I also understand that it's a full service media, you need a good script, good acting, good filming techniques, good score and good editing.
I consider Titanic to be the end of James Cameron's good years, just dull. Sure the technique was OK, but Leonardo DeCaprio is simply not a leading man (especially not then when he didn't look a day over 12), and the story was just not engaging. I call movies like Titanic "sorority girls" they look nice but that's all they have going for them. And the fact that Cameron is still doing Titanic specials for Discovery Channel gives me no hope we'll be getting him back in full form and power any time soon.