Sure YAML is more complex than JSON, but that's because it's more than just a data structure. If you are using it only for things that JSON can do, it's really not that complex.
Agreed. I use a YAML file to track my daily agenda. It was easier to figure out the format, and to leverage existing parser libraries for my reports, than to write my own "agenda-optimized" file format. A good example of http://xkcd.com/1205/.
Which is why the original poster said "the safe version". Simple YAML is simple.