I think that the author of the article specifically speaking of configuration DSLs that were intended to be Turing-incomplete but somehow grew full Turing-completeness and therefore became bastard languages. YAML as a config DSL is sub-par (but I'll take it over JSON any day), and truly declarative, Turing-incomplete config languages are great, as is just using a fully-featured scripting language such as a Lisp or Python, but the middle-ground with a custom config language that is also Turing-complete is usually just bad.

Not sure I have any examples of what that might be. Perhaps nginx? or apache? Lots of complex software have very complex config languages that might accidentally be Turing-complete, but only fools would actually use them like that.