Where in "X-first programming" does that constraint come from? What seems to have happened here is that you read "purpose-first programming", inferred that it'

Where in "X-first programming" does that constraint come from? What seems to have happened here is that you read "purpose-first programming", inferred that it's a methodology for developing software, and then started insisting that the responsibility for your taking that leap is someone else's fault, instead of yours. "Purpose-first programming" makes as much sense as "literate programming".