Traits such as human skin color and height are not suitable for explaining the concept of simple dominance because they are controlled by multiple genes and are influenced by environmental factors. Simple dominance refers to the inheritance pattern of a single gene, where one allele completely masks the expression of the other allele. Skin color and height are polygenic traits, meaning they are controlled by multiple genes that interact with each other in complex ways. The expression of these traits is also influenced by environmental factors such as diet, exercise, and exposure to sunlight, which further complicates their inheritance pattern. Therefore, the concept of simple dominance does not apply to these traits.