What the hell! the reader exclaims. This writer can’t spell! She’s written travelling instead of traveling and centre instead of center and realisation instead of realization. Colour instead of color. This book is crap! It’s riddled with spelling errors and grammatical problems. It’s a bloody one star from me.
No. It’s not riddled with spelling errors and grammatical problems. It’s not written in US English.
Donna Maree Hanson on spellcheck.
So despite being set in Australia, both Liesmith and Stormbringer are published in the US, and thus written in US English. Except it’s US-English-with-Australian-idiom, which means characters describe things as (say) being “a shittonne” rather than “a shitton”, because a tonne and a ton aren’t the same thing, and Australia uses the former. Needless to say, I had some fun discussions with the copyeditor over that one…
The other big example I can think of: “was sat”/”was stood” instead of “was sitting”/”was standing”. The former are common constructions in British English, and sound grammatically odd in Australian and US English.
For the most part, I think US audiences are used to reading solely US editions of books and, yes, these will be rewritten. Which means it’s US audiences who tend to be the ones balking when they encounter non-US English. I’m not sure about the UK, but in Australia it’s kind of a toss-up on whether we get the UK, US, or specifically Australian editions of books (and, of course, if you’re buying print books from, say, Amazon, you’re almost certainly getting US editions). So readers here, I think, tend to be more accepting of grammar and spelling variants.
(The other region I’d be interested to know about would be Canada. I think Canadians tend to use British English spellings, but I’d be willing to bet most of their print books are US imports.)
Tl;dr, pretty much any review you read of the “too many typos 1-star!” variety is full of shit.