Cars can be driven safely, but often aren't.

Alcohol can be consumed in moderation, but often isn't.

Parents can raise kids without being emotionally and physically abusive, but often don't.

Marriages can be healthy and stable lifelong commitments, but often aren't.

Education can help raise people out of poverty, but often doesn't.

Governments can provide stability and security for their constituents, but often don't.

Poor analogies: none of what you describe is often the case out of deliberate action. Perl is often written deliberately in a way that is unreadable or maintainable. On purpose. Often because that’s what the language encourages.

Makes me think we need a new language BNW (brave new world) where all the bad things people are doing in existing languages are simply impossible.

The typical Perl program is half as long as it should be to be readable and maintainable.

Is this an indictment of the language or the developer doing clever, terse quackery?

Mostly the latter.

In the rare occasions when I wrote Perl, the language offered all I needed to make my script as boring as Java, along with many temptations to be clever and concise; many people use Perl because it supports write-only "quackery", but it's their choice.

In Perl's case, it's both. Perl encourages it, and "perl practitioners" as a rule tend to revel in it (in my experience).