From what I have read on these boards over the last few years is that a  lot of people do NOT understand Batman Begins or the Dark Knight or  movies. Some even claim that just because they read the comics that they  understand the characters. They make complaints about how the movies  should be but they are not the one's who make the movie. Just because  some character's don't have much screen time DOES NOT mean that the  character is not done properly.
The only person that is truly 100% happy is the director because it is  their movie. If the character is on screen for only a few seconds is it  is because they are supposed to. What also people DON'T UNDERSTAND is  that  because BATMAN is on screen less time then some character's means  that he is a supporting character in his movie, but he isn't. Bruce  Wayne is the core character NOT BATMAN. Batman is apart of the Bruce  Wayne character. "BATMAN" is also a brand name. Meaning that the movies  and comics or whatever medium the story is being told in, it also has to  tell the arc and stories of the other characters and that pushes  Batman/Bruce Wayne's story forward. 
If you look at The Bruce/Batman character as one character he is the  core character. If a character is not exactly like the comics Example:  the costumes or the way they are drawn or whatever or live/die, people  complain. The comics or source material is just a blue print NOT a  bible. If your doing a movie, TV series, stage show, cartoon, game,  toys, novels, sequels, re-imagining or whatever. They all have to be  different in some way or there is no point. The all travel similar roads  with what happens to them in the source  material but the essence of  the character stays about the same.
It also depends what your influences are. If you grew up in the 60's  with Adam west or read the comics in the 80's, watched the Burton movies  or the animated series,or even Batman Forever or Batman & Robin.  Whatever medium it is still Batman.
It's funny that through the decades in the comics Batman and anything  Batman related has been drawn or presented different as what came before  is usually accepted because in is in a comic, but if it is presented in  another medium it is usually looked down upon. MOST FANS ARE HYPOCRITES  AND DON'T REALLY UNDERSTAND WHY THEY ARGUE. THEY NEED TO EMOTIONALLY  GROW UP!!!