Here are just 3 reasons - I'm sure there are others!
Reason #1: Children's art making experiences, and the resulting
products, are not intended to be "real" cultural objects or authentic
cultural experiences, but aids to help students:
• understand art elements and principles
• develop skills in a variety of art making techniques
• recognize and appreciate artistic conventions of particular cultures
• understand how culture groups created similar products
• understand the historical and social context in which such objects
• recognize and appreciate similarities and differences in the basic
needs of people of diverse cultures...
Reason #2: Artists/craftspersons have always used materials at hand - in
most cases that's what we are doing. Better than that, we are recycling!
Reason #3: Using authentic materials is important within the authentic
culture but neither affordable or necessary for school children's art