I have been telling my students for years that everything matters when it comes to performing a kata: the placement of the hips, the movement of the feet, the retreating hand, the angle of the foot, the depth and width of a stance, the tilt of the pelvis, the breath, the targeting - everything counts. And everything means something. I can't speak for katas that do not come from Okinawa or Japan, but the katas that do come from these countries are a mile wide and a mile deep.
Chado (Japanese tea ceremony) pays homage to the finest details, and everything about the ceremony is focused on these details. The best example of this is the roji - which is the path to the tea house. The stepping stones start out flat but as you get closer to the tea house the stones become rounder and harder to stand on. The purpose of this is to increase your focus and attention as you approach the tea house and the chado within.
The same thought process and attention to detail should be brought to bear when doing your katas.