Beauty is very important to us. Imagine a world without gorgeous sunsets and breathtaking animals. A world without beauty would not be a happy world. We'd all be depressed and unhappy. Emotions would be more negative than they already are now. Some people manage to survive because of some beauty in this world. We NEED beauty.
Mankind has always appreciated Beauty when it comes to Art, classical music or Film. There is Beauty in nature and human kindness. The most thought of Beauty is in one's looks, Some are born with Good looks and that is very practical when it comes for humanity to pass down particular desirable genes. Beauty is practical when it comes to the most lowest common denominator of humanity's nature.
"Form and Function". Generally speaking there is often a way form serves better than function and that outside of marketing for all rights and purposes form is hindered by function whether it be the areas of cost or the areas of actual function.
So beauty is practical only when dealing with sales but design itself rarely manages to be beautiful and at it's peak without any extreme effort or a significant amount of extra materials.