In object oriented languages this pattern is mostly unnecessary, because inheritance is usually better solution for the same problem. Only reason to use something like this in C++ is (maybe even only perceived) efficiency gained by removing level of pointer indirection.
It really comes from functional languages like ML, and is extremely useful and convenient when combined with pattern matching. In fact, attempts to emulate it in OOP using interfaces and visitor pattern tend to bring a lot of boilerplate, and obscure the actual logic, which is exactly what the author is complaining about.
There's definitely more reason to use it than just "efficiency gain", which is why many languages introduced in the last decade have it built in (e.g. Rust, Scala or Swift).
Could you say something about the difference between the two? I'm not aware what it is.
Edit: wow I accidentally a word.
data Choices = Good | Bad | Ugly
class AbstractChoice:
# defines all common operations on choices
# plus potentially some useful stuff on top of those
pass
class Good(AbstractChoice):
# conatins the code specific to good things
pass
class Bad(AbstractChoice):
pass
class Ugly(AbstractChoice):
pass