Why is matching form surface direction and texture direction important?

So texture appears naturally placed on the form

Texture marks should respond to the surface on which they appear. On a rounded form, marks may curve around the volume; on a plane, they may follow its directional structure; and on a tilted surface, their orientation should support the same perspective. When texture direction matches surface direction, the viewer reads the marks as belonging to the object rather than as symbols pasted on top of it. This strengthens the sense of form, material, and spatial turning, so option A is correct. The other options describe opposite or unrelated effects: proper texture does not make every form flat, remove the light source, or turn texture into a title.

This is a Class 9 Art Education question. Chapter: Elements of Art. Topic: Form.