A lot of services are starting to provide information via API calls such as Twitch and Google. I would like to see a built in well documented json parser in mirc. Yes there are scripts out there that already do so but they are kludgy and frequently buggy.

mIRC's scripting language is meant for the purpose of extending the program. Why are you against using scripted handling of JSON data? I feel including handling would cause a cascade of feature requests for other data type handling; XML, GML, YML, and do on. Including such may have a small benefit to some but is mostly bloat to the program as it can be scripted.

As I dev of one such script, I'd like to know what you find as kludgy with the current JSON parsers to better conform my script to what users want.

Well the language can be used for almost anything, and he didn't say he was against a scripter solution, I think he would simply prefer seeing it built-in.
DCX does a very good job at providing much more support for dialog, but having it built-in has been requested many times and would still be a very good thing to have.
Same for JSON or XML imo, which are very popular, unlike GML or YML. I don't see how built-in 'dcx', xml or JSON support would be a bloat.
There are a lot of JSON parser in C which Khaled could use to quickly implement it.