Petabytes of JSON formatted data flowing across the internet every second of every day disagree with your assessment.
(Also, as gets pointed out every time this topic pops up on HN, including multiple times on the submission already, the main demand isn't people wanting to add comments to the JS flowing across the wire, but to config files sitting on disk. Responding to people saying "feature X would help use case Y" by noting how many people are using it for use case Z even without feature X is logically incoherent.)
And many people have. You're literally posting this in response to someone submitting the new spec they created to solve this.
I don't understand what you're trying to argue here.