I wish articles about NLP wouldn't assume by default the language to be English. Many points of this article can also apply to other languages, but may require some more thought. Either other languages should be mentioned, or the title should be "How to Write an English Spelling Corrector".
The assumption is about the audience, not the language.
The author is an English speaker, internal to an English community, writing about spell checking.
Its unreasonable to wish every group on the planet to factor in the concerns of every other group, or add their group identifier to everything they write.
As this is an issue that concerns you, perhaps you could take a fraction of the time the author spent on this article to share some insights on the problems specific to other languages. I, for one, would be interested to read about them.
