Sure, but then you're just adding additional layers to what was supposed to a fairly straight forward script. Much easier to just include everything in a single program so you can just say give path to input json file here, give name of output file here, and run.
Autocad LISP is the one I ran into. At least it didn't 4 years ago. I'm sure there are other niche cases.
Although I'll admit I punted and wrote a trivial 'parser' that was only able to read and write the particular JSON I was dealing with in that project.