Why in the world would I write a parser in bash or awk, regardless of the format? I certainly have better things to do. It doesn't matter how sensible a format is, those tools are simply not appropriate to write a parser in.

I have, however, written a JSON parser before at a previous company in C++ (they didn't want to pull in a library). It wasn't particularly hard.

And yes, like any other parser, it accepted additional non-JSON constructs. This was simply because it was take additional work to error out on those constructs, which would be a waste of time.