So, you are relating the writed of Nightwatch to..... Harry Potter? Ouch man, just ouch.
There were some interesting things portrayed in those films. Not immensely thought provoking for someone who likes to spend much time deep in thought, but still not mindless, either. Though I do have to say, I mostly just found it very weird. But again, most of that comes from translation. I can only imagine that typically the people hired to subtitle movies, are a level of skill lower than those people who translate entire novels, who are generally a level of skill lower than they need to be in order to accurately portray the beauty of the original writing.
It's a tricky equation, where generally the way a book is written, is as important as what it is about. One is incomplete without the other, and in the process of translation, it's as if taking an oil painting, and redoing it as a water color. The brushstrokes are different, the colors are different, and the overall feel is going to simply be different, even if what it portays is still the same.
Ultimately, I think this is what is so great about foreign movies, games, music, etc. The only part that needs good translating is the dialogue, as long as the content is portrayed accurately in the more visual and/or interactive form, then it sidesteps the issues of language.