I wonder if there's an issue of fantasy and sci-fi not having the same status in German literature & TV as it has in the UK or US. There isn't much of a German (original) fantasy or sci-fi book market apart from children's literature and imports from the UK or US for example. I'm no expert and just guessing though, maybe someone here knows more about it?
I don't think the problem is unique to German; Japanese shows dubbed into English have (or used to have) a reputation for bad translations, third-rate voice actors, and censorship. It's gotten better recently as the market has expanded, but most fans still prefer to see the shows with subtitles.