|Cover - Dickens Hard Times, Public Domain|
There can be nothing worse for a writer than someone patronising them, or talking down to them, or even criticising them inaccurately because of misunderstandings about stylistic and spelling differences due to the other writer's national or cultural background.
There are a large number of differences, for example, between the ways that North Americans uses English and how the English themselves apply spelling and grammar to the language.
Personally, I would just tell them where to get off. :)