Unfortunately, that's not an absolute. I've often been told to basically dumb down my writing in my papers because reviewers who are not native English speakers will not understand what I'm trying to say and will feel frustrated. And you don't want to frustrate reviewers...

For example, I once used the plural "lemmata" for "lemma". That is correct English, "lemma, lemmata", although it's much more common to use the Anglicised form "lemmas" (as, e.g. in formulae/formulas). I've also had colleagues "correct" my grammar when I've used expressions like "Absent X, Y occurs" or "X need not be Y", etc.

Sometimes, "excellent" writing is not the goal; writing that gets the point across, is. Much like code, indeed.