But its very vacuousness is what allows optimists such as Mr Smith to see this reform as a basis for an authentic education. I hope they are right, but expect we will find that they are not.
The core of the argument is about the position of subjects. This is not academic pedantry. Disciplines are not an arbitrary conservatism but the outcome of about three millennia of repeatedly renovated wisdom, which has evolved precisely so we can think systematically at all.
ACfE does occasionally declare that subjects will remain important, but that assurance is unconvincing. Where are its detailed discussions of the nature of mathematics, or the grammatical basis of cogent expression, or the essential characteristics of scientific knowledge, or the nature of the literary canon, or the fundamental facts and concepts that constitute historical understanding, or sport and drama as goods in themselves rather than handmaidens of other things?
Where is the recognition that engaging with any of this in a worthwhile way is difficult, not fun, and indeed worthwhile only to the extent that it is difficult? If (with the fashion) we reject "direct teaching" as a matter of principle, how are students to gain a sense of how these bodies of knowledge cohere?
The reply will come that none of this is excluded, and that is true - but disingenuous or dishonest. It is disingenuous to the extent that the reform is then relying on teachers to provide the intellectual infrastructure without which we cannot engage in the traditions of thought that our predecessors have developed to make sense of the world.
It is dishonest if all the credit, the inspectorial praise, the avenues of promotion - and political influence - start to go to those whose meretriciousness conceals their ignorance of what has truly gone before.
Mr Smith graciously acknowledged my defence of Scottish comprehensive education. What that remarkable reform (and its precursors) did achieve was an extension to previously-marginalised groups - girls, working-class people, Catholics - of the best that has been thought and said. The reform still is worth defending for that.
But gradually in the last couple of decades, we have fallen for the abdication of intellectual responsibility that has grown to engulf most of the English-speaking education world - the belief that cultural achievement is the reason some students have been excluded, that learning has been no better than a white, middle-class, male imposition. This betrayal took a while to wash up on Scotland's shores, but it has arrived with a vengeance.
That insidious view is not explicitly present in ACfE, any more than it was officially part of Higher Still. But it lies behind the insistence that the curriculum is the "totality of experiences which are planned" rather than the expert embodiment of knowledge and concepts, or in the belief that vocationalism and other kinds of instrumentalism are necessary and sufficient for a worthwhile system of schooling, or in the obsession with self-belief as a pre-requisite of learning rather than a consequence of struggling with intractable ideas and standards of performance.
If we persist, we will destroy comprehensive education by accident, because people who care about worthwhile education will turn to different institutional arrangements.
Traditions of knowledge never just die: they are eroded until nothing is left. Consider what we have done to Latin in the last three-quarters of a century. Once gone, they are difficult to recover, because we will by then have created a society that simply does not care.
Lindsay Paterson is professor of educational policy at Edinburgh University.