There are parsers which allow for comments if one wants, so if someone wants to engineer an insane system no one is stopping them, provided they can ensure the parser on the other end of it.
This is a data format meant to be readable by humans. As such, it's natural to want to support things like configuration via end-user editing values in the text as a use case. Data is occasionally going to need comments to explain valid options or add context for people to edit. This is a reasonable thing to have.
There are parsers which allow for comments if one wants, so if someone wants to engineer an insane system no one is stopping them, provided they can ensure the parser on the other end of it.
This is a data format meant to be readable by humans. As such, it's natural to want to support things like configuration via end-user editing values in the text as a use case. Data is occasionally going to need comments to explain valid options or add context for people to edit. This is a reasonable thing to have.