Why Must Hollywood Ruin Everything?

I hope everyone has had a chance to read the Millenium Trilogy by Stieg Larsson. They made a movie (Swedish) based on the first book "The Girl With the Dragon Tatoo". It was fantastic, it is one of the very few instances of reading a book and then seeing the movie where I have not walked away seething in rage.
I was nervous when I heard that Hollywood was going to film American versions of the books. I expected the usual tripe you get from Hollywood, incredibly pretty actors and actresses who either can't act or in no way fit the role. Well, Hollywood disappoints (or is that fails to disappoint) once again. They tagged Daniel Craig to play Mikael. I admit not the worst choice, but not the best. The choice of Lisbeth is where they dropped the proverbial ball. They chose Rooney Mara (picture here). Don't mistake me, I'm sure she's a wonderful actress and a lovely person, but WTF? She looks like the girl next door, who happens to model in her spare time. So I ask again, why must Hollywood ruin everything?