Pixelfish had this to say in comments. I could not let it languish there:
At what point did publishers start getting anal about the usage variations between the US and all other English speaking countries? Because my original copies of the Chronicles of Narnia had English spellings, but my new ones don’t and are in the wrong order. My Canadian copies of Harry Potter have the Britishisms intact, even though they don’t use all the slang, but the US ones don’t. I liked it better when US YA publishers let me find out MORE about the world instead of LESS. Part of the reason I read was to get away from my perfectly safe little Utah neighbourhood. But I digress . . . oh boy, howdy, do I digress.
I have no idea when that started. But it is a Very. Bad. Thing. I disapprove. HEARTILY.
Back at home I grew up with books with Commonwealth spelling and also with USian spellings. So Enid Blyton & Patricia Wrightson = colour. Nancy Drew & Hardy Boys = color. Though sometimes the punctuation would be changed.
I really hate the way many US publishers USianise things. I was just reading the US edition of an Australian book set in Oz with Oz characters. Except that the characters compared things to the size of a dime. (We don’t have dimes in Australia.) They discussed each others height in feet and inches. (Australia is metric.) The distances they drove were in miles. (Ditto. We have kilometres.) They used no Aussie slang. Everything that could be even a tiny bit confusing to a US reader was changed.
It drove me crazy. I stopped reading the book. I’ll read the Australian edition when I go home.
How stupid do publishers think readers are? We can figure stuff out from context. If we don’t know stuff we can look it up. Part of the fun of reading a book set in a different country is learning about the differences. Changing the spelling, adding “dimes” and “quarters”, removing all the local slang, wrecks the flavour and rhythm of the book. I think it’s a dreadful editorial decision and I wish they’d stop doing it.
Er, what you said, Pixelfish.