Also, data being interpreted different based on region/language settings is a sure way to end up with bugs, so I think its a terrible thing that Excel does this.
b) There is no "." on the num-pad for German keyboard layouts, they have a "," the German decimal separator.
It's not "techies know best" whining. We've been increasingly computerizing the economy for the past 50+ years; it's past time for societies to adapt to that reality, instead of wasting time and money on dealing with dozens of date formats, number separators, currency notations, etc.
The US switched to the metric system in the 60s and there is a shitload of benefits in doing so. Has it worked? Not really. Still using the old system everywhere.
So the solution cannot be to get rid of locales, but to actually use them properly:
- Always use the right locale for the job (the OS or browser should be the oracle for the right locale to use)
- Read the data in the user defined locale
- Store the data in some canonical form (e.g. store numbers as number types instead of strings, use ISO-8601 for dates, ...)
- Write the data to the user defined locale
And then, there's the problem of users - whatever locale they have set in their system were most likely not set by them, and are often misaligned with what they're naturally using.
There's a lot of bugs and issues happening to people every day that could be removed if major software vendors said, "sorry, the only allowed input format for date is ISO8601, and dot is the only valid decimal separator; take it or leave it".
Furthermore, I would argue that the very notion of user locale based localization by default is misguided, since it is fundamentally no different from automatic translation of content based on the users' UI language setting. It is a form of misrepresenting the content, though with things like dates you usually don't lose much information in the process.
The problem doesn't even have a correct solution, because the locale settings in the OS and the browser aren't often set by end users (a regular person probably doesn't even know that they exist) and the defaults depend on many random factors (like which store you bought your computer with preinstalled Windows from).