Final answer:
The option that is not a reason for estheticians to understand makeup is 'To perform surgical procedures' as their expertise focuses on non-surgical cosmetic enhancement.
Step-by-step explanation:
Option D, 'To perform surgical procedures', is not one of the reasons estheticians should have a thorough understanding of makeup. Estheticians are trained in the art of enhancing a client's appearance through skin care and makeup application, rather than medical or surgical interventions. Understanding makeup allows estheticians to recommend suitable products to their clients, enhance the client's natural beauty, and correct skin imperfections through non-invasive techniques.