It really shouldn't be, though. I.e. not unless you're parsing or emitting it ad-hoc, for example by assuming that an expression like:

  "{" + $someKey + ":" + $someValue + "}"

produces a valid JSON. It does - sometimes - and then it's indeed easier to work with. It'll also blow up in your face. Using JSON the right way - via a proper parser and serializer - should be identical to using YAML or any other equivalent format.