After thinking about it and reading the other answers (thank you Lauren and mootinator) I came up with a possible explanation. I don't know if it is correct though.
It can be - as often - about money. It makes not much sense for European/Indian/Chinese filmmakers to produce a remake of a Hollywood-movie (at least directly after the original), as everyone already knows the original movie. Hollywood has excellent distribution-channels and reach most of the world.
That's a completely different situation for non-US-filmmakers. Even in Europe it is hard for foreign European movies to make it to the cinemas. And even if they run in the cinemas, they do only with few copies and without big advertisement. I didn't know about 'Open your eyes' before I heard about 'Vanilla Sky'. I wouldn't know about '[rec]', if I wouldn't go to festivals. That are Spanish movies, and I'm German, so even European movies have a hard time to distribute in other European countries.
So there is a possibility to make money for producers in Hollywood. As they have access to good distribution-channels and have some advertisement-budget they can reach a new big audience and can make money. And it is not very risky, the original movie already showed that it can be successful at the audience it reaches. So, if it is possible to make money, someone will do.
That would explain the relative high number of Hollywood-remakes of foreign movies. And it would mean, that they are actually a good thing, because they bring good ideas to more people.