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.
Often the turing completeness comes not from the config _format_ but from the semantics. A good example of this is Logstash config, where your config is an array of steps to apply, each of which can filter things in certain ways based on certain conditions, and before you know it you've used 100 lines to badly and buggily implement a 5-line script in a real language.
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.