It’s not punting on the issue. We are very well aware of the limitations of the current approach. There are reasonably well functioning libraries for doing what you want, they just happen not to be part of the standard library, and for some of them, for good reasons.
With the time I just find it amusing that most of the people getting an impression on OCaml almost always mention this “unforgivable” sin.
But the reality is that in the set of languages out there that do have a type for Unicode strings in their standard library, very few of them have a non broken one (the only ones I know for sure have not a broken one are Swift and rust).
I personally don’t see much difference and even prefer almost no (and hence sound) support rather than broken support — e.g. JavaScript, Python, Java, etc. in which you may have a type for Unicode strings but can’t do a) for Unicode scalar values, i.e. the actual textual content, nor answer c).