Or commenting JSON?

Err, yes? Is quoting your keys, delimitation members with a comma instead of whitespace, and putting brackets/braces around collections really that confusing that people struggle to edit it by hand or read it in a diff?

I think the syntax is actually what makes it more human readable, it's still 95% text/numbers just annotated with information that makes it clear what things actually are instead of hiding them behind confusing computer parsing rules nobody is going to think about while reading human-friendly text.

That's probably the biggest thing YAML has going for it and probably the only feature I take advantage of when something takes YAML instead of JSON.