That's npm, not node itself, that relies on package.json.  When its creator chose it, 
  he knew exactly what JSON is.  He's maintained on HN and elsewhere that he made a good
  decision.  So even if you stop calling this JSON, he's not buying it.

Going along with this, there are other formats that lend themselves extremely nicely to being human readable/writable/parsable. I've seen YAML (http://en.wikipedia.org/wiki/YAML) used out in the wild to support these sorts of use cases, often in systems which also leverage JSON.

Edit: Not saying the author of npm is wrong for picking JSON, just that there already viable serialization alternatives expressly designed with human factors in mind.