Dating is usually for teen and above, who are young. So, young hearts and minds would get attracted to appearance first, then might go deeper. But the true beauty lies within, which people take time to understand. May be that's why, looks matter to guys and girls.
We are humans and physical appearance does matter whether we admit it or not. Of course, there'd be exceptions to everything wherein appearance is totally disregarded and emotional and personal love and curiosity is expressed and exchanged.
It depends a lot too on the morality and preference and perspective of a person when it comes to "appreciating beauty".
In a moral sense a person can like and look at a disabled or physically impaired person the same way as a normal person and see that person for who he or she is on the inside. Preference, when people appreciate beauty in a subjective manner with certain "likes" to how a girl they like should look like.