The opposite; case insensitivity is what human brains do, we read word WORD Word and woRD as the same thing, it's computer case-sensitive matching which is "brainless". Computers not aligning with what humans do is annoying and frustrating; they should be tools for us, not us for them. There's no way two people would write ö ö and have readers think they were different because one was written in oil-based ink and one in water-based ink, or whatever compares with behind the scenes implementation details like combining form vs single character.
I have just been arguing the same thing in far too much detail in this thread: https://news.ycombinator.com/item?id=29722019