I'm not super invested in this debate one way or the other but arguing a comment should be part of your data rather than documenting what data is contained is a bizarre take on the question. Either be of the opinion it's a data format and comments are just out of scope (and using JSON for e.g. config is just a bad choice), or agree that allowing comments in JSON should be part of the spec since right or wrong it is used for config and other human edited use cases. JSON5's adoption seems to imply people are mostly on the latter side of the fence.