And to further apply semantics to this just to be snide, the value is only "missing" if it could possibly ever be defined for that tuple. There are cases where you expect the value to be "missing", and it not being "missing" would be considered a data integrity issue. Fun.
The fact that the XHR/network console on Chrome doesn't format JSON responses is insane. Your in the most popular browser in the world and you have to copy paste the JSON into a formatter to read it?? Really??