Humans need aesthetics in their lives, even if it's just well-designed functional objects, or natural beauty, such as trees and flowers.
Imagine you live in a concrete-block building. The walls are plain white plaster. Your bedding is raw white cotton. Your clothes are a simple gray jumpsuit and comfortable shoes. Your hair is shaved off, because shampoo is pointless. Your food is packaged in monotone containers that say "BREAD", "MILK", "VODKA" etc.. You ride a bus or streetcar to work (cars are wasteful). The vehicle is a plain metal box, as it never goes fast enough to encounter wind resistance. Your commute takes you past barren asphalt streets, lined with plain storefronts that say such things as "GROCERY", "SHOE SHOP" and "DRUGSTORE". The businesses are all the same because the government runs them all, because competition is wasteful. The elevator up to your office is a metal box with handrails on the inside. The halls are of concrete, with fluorescent lighting designed to provide the minimum brightness. You work at an unadorned desk, made of aluminum or plywood. Your computer has the simplest of GUI's, and the only programs are a basic office suite, email, and whatever is related to your work. After work, you and your lady friend meet at your apartment for dinner. She brings her own rations, because you don't have enough for the both of you. You try to talk about your respective days, but they're the same as all the others. Afterwards, you make love in the positions described in the sex ed. classes given in school. Then you fall asleep, and the day repeats itself.