Json is very convenient to glue tools together.
For example, both python and powershell have ability to serialize and de-serialize anything into json without a schema.
Unfortunately, after de-serialization from json in PowerShell, you get immutable objects.
If you just get mutable hashtables, life would be much better: i.e. you can create some object in python, toss it to powershell, enhance with some info and inspect the complete result.

One of the date points about a similar request: http://stackoverflow.com/questions/3740128/pscustomobject-to-hashtable

It's a more generic question, but I think that in context of json it's especially desirable.