And that’s what the IETF uses but djb doesn’t like.

It's literally the ethos of the IETF going back to (at least) the late 1980s, when this was the primary contrast between IETF standards process vs. the more staid and rigorous OSI process. It's not usefully up for debate.

He doesn't like it at least in part for lacking a concrete definition. Attempting to pin down what it means or ought to mean is therefore useful.