Earlier quoted context omitted.
Counterpoint: In practically every language that supports comments, these "comments" are now used for language extensions (IDE folding markers, eslint-ignore, FPGA synthesis hints, ...) Please don't do that to JSON.
What exactly is wrong with that? Comment hints like that are quite common and with a few exceptions (synthesis hints) they are all optional hints that have no effect on the main interpretation of the code. IDE folding markers aren't going to hurt anyone. Chrome doesn't care about lint waivers. Etc.
I think folding/lint/etc. markers are poor examples here, because they're basically annotations for other tools which seems entirely fine.
However comments that affect the behaviour of the code itself are really much less fun to deal with.
Worrying that JSON implementations would end up acquiring the latter is pretty fair given our track record as a species.