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.