then you duplicate all these settings in all applications.Isn't this the reason why it was designed so that it is set at the system level and applications take over this setting? In the other words, set it up once and use it many times.
I really don't see a reason why I should have it set as I live in the UK and use English when I don't want the UK setting to be used?The only reason is that the computer is managed externally from some other country.But in case of personal use, I don't see any reason to do that.
Because it is much easier and more convenient for the user to make this change to the single application than to the entire operating system. Whatever the reasons are.