The hard traces from tribal, pre-historical, greek vases, for exmple, are associated with nobility, strenght, innocence and sincerity. And the "soft" traces that art have being developed towards the imitation of nature was identified with vulgarity, effeminance, corruption and meretriciousness.
To have an idea how this actually was effected, we can see that usually tribal, pre-historical and even medieval religious works and expressionism, with their hard traces, they have the meaning to reach not the material or the physical but the essence, the transcendence, the ideas. While the perfect Greek sculptures and the renascence works and culture was looking to reach the material, the goods, the meaning of being strong and beautiful or the meaning of have possessions and power. Even saints in the renascence paintings are pictured as desirable, tangible, Noble.
While during development of art it appeals to the mundane pleasures, the primitive has the sense of pure and innocence beyond the material appeal.