I didn't say it's unacceptable, neither meant that. In many contexts, it'd be tough without case-insensitive regex matching, for example. Reinforcing my point, //i gains issues once applied to the entirety of Unicode.

It's almost comical: people continue insisting on "letters not code points" knowing very well how computers are bad with guesswork and under-defined notions. Issues stemming from that keep coming up. What if, instead, the norm accepted that 'A' ≠ 'a' and stopped creating problems which computers are known to deal poorly with?