Maruti has not updated Eeco’s design significantly in over a decade, why?

Ever since its introduction, the Maruti Eeco has remained largely the same boxy design but with minor updates over the years. Other cars in Maruti's lineup have seen major redesigns but the Eeco looks stuck in time. Unusual in the automotive world where regular facelifts and redesigns are the norm, this lack of major design changes is the first. Is Maruti deliberately keeping the Eeco’s design unchanged, and if so, why? So is the unchanged design part of the appeal or is it holding the vehicle back? Why has the basic design remained the same for so long if there are practical or economic reasons for doing so? What effect does this strategy have on the Eeco’s market position and consumer perception of it?