The reason to have sleek exteriors or to look cool is because you need be aerodynamic (because you're in the air) or need to look cool (because you're in a movi

The reason to have sleek exteriors or to look cool is because you need be aerodynamic (because you're in the air) or need to look cool (because you're in a movie, or you're a consumer good). Being neither in much air nor in a movie nor a consumer good, real spacecraft don't bother with expensive, constrictive, and (more importantly) heavy exterior shells. Instead, form follows function.