I'm not entirely sure I understand you. Do you find it bad that there are several options?

I had the feeling that YAML is the one that addresses your criticism ("I like YAML as configuration file language, but it's terrible for DSLs."). And yes, I do use the python one and I am very happy with it.

> The YAML is the default, and it's what you find examples and support for (Stack Overflow and so on)

Pro tip: if they are YAML on StackOverflow, you don't have to copy-paste them, but more rather translate them to the representation that satisfy your high requirements.