I think parsers for JSON and Yaml, INI etc should be designed in such a way as to make it impossible to assign anything like an object, class, function, etc. Numbers, strings, and collections of numbers and strings... that's all you should get (though obviously "string" is frought with peril.) Anything more is unnecessarily complex.
The way to have avoided the issue would have been for JSON to have a grammar that broke eval(). But one could argue the ability to pass JSON into eval() to get JavaScript is one of the reasons JSON became popular to begin with.
