Tiger Dingsun and Nelson Goodman have inspired me to consider "world-building" in really broad terms, as the simple act of defining an ontology. You might say we engage in world-building when we:
— organize a file cabinet
— plan a daily routine
— explain our jobs to people
— create an outline for an essay
— design a syllabus
— build a template to be customized by others
... and so on.
I think this world-building has a sort of innate appeal to us — or to me anyway.