I don't know who came up with "go/no go", but I do know who came up with "stay/no stay": Bill Tindall.
In one of his famous "Tindallgrams" he pointed out the very understandable confusion that might result if somewhere were to yell "GO!" after a successful lunar landing. Did it mean everything was fine, carry on with the nominal mission, or would it mean "Get off the lunar surface right now, while you can?"