Onur Cobanli explains:
Good design is complex; even if the final physical form looks simple, it is result of past experience, research, studies, prototypes etc; most of the time people judge the design based on the looks, however for example durability, sustainability and all other aspects and decisions embedded into the product are also part of the design; thus great design while it may look simple, indeed requires complex and complete thinking. Simplicity is just a mask.