Purely from an aesthetics standpoint, I'm guessing its because they have a tendency to form quasi-repeating patterns and long rivers which are generally unsight

Purely from an aesthetics standpoint, I'm guessing its because they have a tendency to form quasi-repeating patterns and long rivers which are generally unsightly (which is subjective): The long string of horizontal yellow diamonds and upside down blue "darts" in this image: https://upload.wikimedia.org/wikipedia/commons/thumb/4/40/Wang_tesselation.svg/1024px-Wang_tesselation.svg.png https://upload.wikimedia.org/wikipedia/commons/thumb/4/40/Wa... Or the red "dominoes" in this image: https://grahamshawcross.files.wordpress.com/2012/10/13tiling1.jpg?w=640&h=974 https://grahamshawcross.files.wordpress.com/2012/10/13tiling...