I disagree. Yes it is human readable if you just want to read the words (like your would with Markdown), but with a configuration file you want to understand the structure. YAML makes that quite confusing IMO. It seems like a random array of dashes and indentation.

JSON is much more human readable in that respect because the structure is explicit so there's no ambiguity. I'd say TOML is somewhere in-between. But both are vastly preferable to YAML because they don't have Javascript-style type insanity.