Comment by tuveson

As a data/serialization format (the original intended use of JSON), I think no comments is the right choice, since adding comments introduces a bunch of questions about how comments ought to be parsed into a datastructure (or if they should be sent/(de)serialized at all). But for config files the lack of comments is the wrong choice, since typically you want to explain why things are set the way they are. The lack of ordering of entries also makes total sense for data/(de)serialization, but makes no sense for a config. I think the problem is people are lazy and just want to JSON.parse() everything, and used JSON in places it doesn't belong, like config files.