It will also prevent damage to posture and hip alignment from the legs having too different heights (the artifical leg is usualy adjusted to the natural one when barefoot).
Plus there is reduction of wear on the soles, especialy when the feet are pure metal (as is the case with Karma's) or plastics.
Not to forget that wearing clothes over the prosthetics offers protection from dust, dirt and liquids getting into the joints and other mechanical parts, and the design often given to Karma's leg has many mechanical parts openly visible.
Also what worked well for Forge ever since his introduction should work right for Karma aswell.
This aswell.