I thought I was clear, too. In fact it's something I've stated twice now. One more time: the English translations that have been in circulation for decades around the world are the Little Brown editions that use a British idiom. Thus there are generations of Tintin fans in the English-speaking world whose perception of the characters is drawn from those editions. The movie matches that, thus delivering an experience that should be gratifying to fans, far more so than an Americanization that stands at odds with the style of the English translations.
I'm personally pleased that's the approach they've taken as it will more closely match the translations I grew up reading, and I think it's the best choice commercially since films with British accents face no special obstacle at the US box office and the British idiom will sit better with Tintin fans in foreign markets than an Americanized product.
If we were talking about an adaptation of a French comic book series which had never been translated into English or which was virtually unknown outside of France and Belgium, then I'd agree that there would be no qualitative difference between an Americanized and Anglicized film adaptation. But that's not the case with Tintin, where the British idiom has long been firmly established and is rooted in the minds of generations of readers around the world.
