Honestly, it may be due to the movie being considered too "mainstream", popular, or successful. There seem to be many, MANY film critics out there who see blockbuster movies like Titanic or Avatar to have less quality than certain art house movies or some of the less mainstream films. Look at the Academy Awards over the past few years.
They seemed to have shifted their focus from higher grossing blockbusters to lesser known films that still tell compelling stories. That's not to say that Titanic had a bad plot or a cliche one, but there are prejudices among critics against these kinds of films.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.