[...] One argument for case-sensitivity, in internationalised software, is that it neatly side-steps all the clumsiness and complexity of dealing with case issues in multiple characters sets and locales. It makes the programmer’s job a lot easier by not trying to find the corresponding upper- (or lower-) case character from the user’s input. [...]

Still bearing with you, Julian. But if you don’t come to the point soon, my head, unsatiated curiosity will develop into intellectual vacuum, and my head will implode.

I find Unicode fascinating just for the window it provides onto the range of human written expression. As you have seen, even the most basic English assumptions (like the characteristics of upper- and lower-case letters) do not hold for the rest of the non English-speaking world.