How are Aircraft Noses Designed?
Aesthetics are by far and away the last thing aircraft designers are optimising for. A better question might be, why do aerodynamically-efficient designs look pleasing, but that would likely be an art or psychology question and off-topic here.

Since aircraft could travel at appreciable speeds, designs have focused primarily on drag reduction. Smooth curves and teardrop shapes on the leading parts of shapes help with this. Before 3D fluid modelling software, this kind of design would be achieved using a combination of fluid dynamics computations done by hand, wind tunnel modelling, and likely a bit of intuition.