I think it's only partially true. Technology products may get pretty depending on who is the consumer. Computers, phones and cars get nice exterior design, because the "general public" uses them, and they are, as you said, sold on looks.
But consider industrial machines and buildings: mining machinery, electronics assembly lines, car factories and oil mining platforms. No matter how mature an industry branch is, machines are not being built to look nice. And warehouse buildings are just huge, gray, ugly-as-hell boxes. This is because there are many other constraints, machinery gets expensive, and there's simply no use for aesthetics.
So I think that spaceships may get nice exterior design if a lot of people (think millions) is going to be buying them. If the consumer group will be small, we will get aesthetics closer to cargo trains. Which, in my opinion, is awesome anyway.
And yes, I too think that ISS looks great as it is.