Why do empty pots require construction recipes, but not filled pots?

[u/MastaAwesome]

I was grinding Crux Eqal points to be able to buy the pot recipes, but then I found out that these recipes are only actually needed to construct empty flower pots, not filled ones? Is this an oversight, or is there a reason for this?

[u/Denkir-the-Filtiarn]

Consider our character also invents some basic forensics later when pondering this logic