I received this feedback as a comment to a now-deleted/closed question. Please illuminate my lack of understanding; is the "crypto" prefix a misnomer in some cases of digital currency or is there another meaning not related to hashing algorithms, etc.?
The question was closed and deleted by the post author, is thus generally not viewable, and thus scheduled to vanish. My feedback in comment reads (with disputed assertion bolded):
Sorry, but "How important is the DAG data structure to the future of our world, given that it seems to be central to technologies which are revolutionizing it?" is opinion-based, and only distantly related to cryptography. Mind you, a concept being used in cryptocurrencies does not make it related to cryptography; which is our only subject. Please make this a factual cryptographic question, or remove it. See this meta on cryptocurrency-related questions.
Argument towards the disputed assertion: the concept of currency is obviously used in and related to cryptocurrencies; yet it's far from as obviously related to cryptography, per Merriam-Webster definitions of cryptography and related.
Admittedly using mathematical terms out of their charted territory: "related to" is a symmetric but non-transitive relation.
My comment and assertion were intended to help improve the question. I later realized I once used DAGs in a cryptanalytic attack (that's far from typical), and IIRC then rescinded my first and perhaps hasty closing, thinking it was possible to improve the question.
A comment by another contributor justifies closing the question with: "because it is a general and non-specific question about an elementary data structure used in countless applications throughout computer science, not just cryptography".