In fact, the problem is a bit broader than it seems if we're talking about languages other than English. That's why Amethyst's approach makes sense 😳
Discussion
> 'こんにちは'.toLowerCase()
"こんにちは"
Seems fine
That's exactly the point—it's unethical concerning the English language because this decision is selectively discriminatory. And writing systems without distinct upper or lower case do not undergo the correction required for the English language, putting them in a privileged position.
From this perspective, what Amethyst is doing is progressive and fair.