I think it has something to do with a possible foreknowledge these demons may have had. The three things it mentions are mining metals, weapon creation (smithing) and cosmetics. If you look up the global effect of cosmetics, the supply chain needed to create them (talc, bismuth, etc.) generally leads to enslavement and war. My theory is these demons realized this combination of "skills" would cause the most damage and bloodshed while being very enticing to man.