If you actually think physical attractiveness is important in a relationship, you are not shallow. To make a good relationship last you have to be physically and mentally attracted to the person. I am tired of seeing people being called shallow simply because they are looking for someone attractive to them, mentally and physically.
You are shallow when physical attractiveness is the only thing that keeps you two together.
Basically. Initial attraction to a person is usually physical anyway. All the other stuff tends to come after introductions are made.