"Player can craft a X, so they should also be able to craft a Y"
This kind of argument is invalid for several reasons.
- Just because there’s a contradiction i.e. “cordless drills and gunsmithing tools are equally hard to make, but we can only make cordless drills” doesn’t imply that the correct action is allowing crafting of gunsmithing tools, it’s equally likely that craftable cordless drills were a mistake.
- This argument generally has a tenuous or non-existent relationship between the items in question. Frequently it’s an assertion that X is “complicated” and Y is either “simple” or “also complicated”, this is not sufficient for craftability of X to imply craftability of Y.
Hoisted from a topic where it came up again: https://discourse.cataclysmdda.org/t/i-cant-see-the-difference-between-firearm-and-gunsmith-repair-kits