There are some reasons, but they lie outside the undeclared assumptions contained in the language of the question.
Proportion also plays a large role in the human perception of beauty.
Making boat parts the truly correct size and shape often results in the perception of beauty of the whole. Many artifacts that are perfectly evolved and time tested are often quite beautiful, but usually as a by-product of functionality rather than concious creation. Arriving at beauty from the opposite direction may be the quickest route of all. Everything you do in the course of construction is seen by you, and your boat. That's two too many already.