Yes, it would have been great if J.I. Packer had produced a systematic theology. But who says that he needs to? While acknowledging the theological acumen of J.I. Packer, Professor Carl Trueman calls Packer a “failure” for not producing a systematic theology.
Professor Trueman is wrong. As professor of historical theology and church history, Trueman should know that a systematic theology is not the only path to leaving an enduring legacy. Ask Luther, Edwards and so on.