Well if you're really going to go down that route, you should remember that the "unix philosophy" favours plain text as the data-passing mechanism. JSON itself does not have rules for how things like malformed UTF8 decoding should work, which means that every implementation of this JMAP protocol is going to need to refer to a specific JSON spec for starters, which is already destroying the credibility of the "simple" argument. Also, I don't see how your claims about hackers "in those days" has any basis other than speculation here.