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).