But they're hard to read for anyone who isn't an expert on not just the language but the type in question (c.f. Rust's Option() idioms all looks like line noise to newbies, etc...). And that's a bad trade.
In essence, this stuff is just Perl all over again. It's a language feature that prioritizes concision over comprehension. And I say that as someone who really likes coding in perl. But "people" don't like perl, and the community moved on, and the reasons are... the same reason that uptake in ADTs is lagging where the experts want it to be.
