I don't get why they change it for Americans, either. I'm going to take a different example and mention "Sorcerer's Stone". Personally, it's annoyed me, since I figured out the slang was 'translated', that they did so, because, at least in the copy of the book I have, it changed the line to "Why had Dudley always been able to kick him around like a football?"
That line never made sense to me. Until I was told the slang was translated and learned enough Brit!speak to have a mental image of a black-and white, round ball.
That line never made sense to me. Until I was told the slang was translated and learned enough Brit!speak to have a mental image of a black-and white, round ball.