You still have to learn the syntax even if it is expressed in json or yaml. Perhaps stating the obvious, but not every json object is a valid ntp configuration.

You still have to learn the syntax even if it is expressed in json or yaml. Perhaps stating the obvious, but not every json object is a valid ntp configuration. The configuration object will always and by definition be proprietary to ntp. Expressing it as plain text allows for a trivial parser, without any of the security implications of wrapping it in a general language language ("should this string be escaped?", "what should we do with invalid utf8?"). The more simple format has survived over thirty years, is trivial to parse by anyone, and does not bring any dependencies that needs maintaining. That should count for something.