Why are many languages case sensitive?
Is it simply a matter of inheritance? C++ is case-sensitive because C is, Java is case-sensitive because C++ is, etc.? Or is t
Case folding is only simple in English (and for all characters < 128). The German sz or "sharp s" (ß) doesn't have an upper case variant in the ISO 8859-1 charset. It only received one in Unicode after about a decade of discussion (and now, all fonts must be updated...). Kanji and Hiragana (Japanese alphabets) don't even know lower case.
To avoid this mess, even in this age of Unicode, it is not wise to allow case folding and unicode identifiers.