Why is Luster not a good characteristic to use for the identification of minerals?

Luster means to give shine to a surface. Luster is a general idea of a mineral but you may need to be more specific. By specific I mean what kind of luster does the mineral have? Metallic, Non-Metallic, Vitreous, Resinous, Pearly, Greasy, Silky, or Adamantine. These are more specific types of luster than just saying luster.