Yes, in my country we use spaces to separate thousands and "," is used for what the decimal point does in the US. In my handwriting I use that notation.

However, from a computer, I (and I'm certain I'm not the only one) actually expect it to output the US notation.

I'd much rather have a computer always output the same format (and that happens to be the US format), than try to be smart with locales, when the end result is that some things will do this, others that. Makes stuff harder to use, and when programming, harder to parse.

I've once had to touch Excel on a Windows machine configured for a non-US language, and it refused to import a CSV file that had commas, even though CSV means comma separated values. It required semicolons due to the locale settings of Windows. This stuff should not happen. A CSV is meant for computers, and to be interchangeable, not to use different types of commas and refuse to work with other types depending on user locale settings...

Of course, when publishing or printing, that's a whole different matter, and there it better get the locale of your country perfect. But this here was about output in the console, which is often meant as input of other scripts etc...