Earlier quoted context omitted.
I wouldn’t say it’s irrelevant. If you are speaking to someone over a phone, over a counter, or through the mail, they interpret your communication through the same lens of assumptions, before it even reaches your application.
That's why I said rather ;) Human assumptions are one thing, but if you're directly speaking to a person, you can explain your unusual name situation. There is no discussing with the input validation on a web form, though. That's why I think it's far more important for programmers rather than, for example, counter staff.
Sort of. I'm more thinking about situations where the person makes interpretive assumptions on their own without opportunity for discussion. You don't normally see what people are actually filling out in the application when you're talking to a customer service representative. Nor would 90%+ of western CS reps have any clue what you're even talking about if you brought up even a very common exception.
Example:
Form: [first name] and [last name]
CS Rep: what's your name?
Customer: "Kim Jong Un"
Resulting record: {firstname: 'Kim', lastname:'Un'}
And even if your developer was smart and made those fields "given name" and "surname", your CS rep might still jam the values in the wrong fields because they're a kid in Nebraska making $12/hr who barely understands the difference between Korea and China.