Seeking from my own builds, I like to make something that I am proud to look at. AND does its job. I want something I built to both reflect how I want myself to look to others, and my skill as a systems designer. The only way to do that is to strive to achieve both beauty and function.
When building like that however, there will always be compromises. Can't look quite as amazing because you need a lil extra room for power. Can't have that extra 1k worth of shield capacity because it would ruin that amazing profile your ship has.
Necessity is the mother of invention. Thus the necessity to build for looks, and function always push me to get just a little bit more out of each. It pushes me to be more creative in how I build. And that, overall will make me a much, much better ship systems designer, and a better hull designer. To me, divorcing one aspect of building from the other would be like taking bread away from a sandwich, or taking the insides away from the bread.