Personally, I don't like it. I prefer English function names.
However, the most annoying thing about Excel localisation is that the behaviour of CSV import/export changes depending on the OS locale setting. It doesn't even let you override it. You actually have to change the OS settings to get the English behaviour.
Might be wrong on this one but I thought that I had heard that this was not the case in earlier versions and if you opened a German excel file on a computer set to English it would fail.
If you made all keywords fit one character or so and allow selective installation of dictionaries, that would probably also decrease source code form size significantly! That would be great even if you never were to use any language other than English. I’ve played with APL a bit and found out that one can configure Emacs to replace APL’s cryptic symbols with English words using this: https://www.emacswiki.org/emacs/PrettySymbol
APL is however not a language that one would consider using seriously.
Personally, I don't like it. I prefer English function names.
However, the most annoying thing about Excel localisation is that the behaviour of CSV import/export changes depending on the OS locale setting. It doesn't even let you override it. You actually have to change the OS settings to get the English behaviour.