In wuxia, it often seems that half the external unarmed combat arts are palm attacks: Hong Lung 18 Palms, Heart-Penetrating Palm, various Shaolin palms, Iron Sand Palm, Sad Palm, etc. Palm, palm, palm.
In real world Chinese martial arts, however, the open palm doesn't seem to have much of a place. You'll much more frequently encounter closed fist techniques.
Why do wuxia martial arts emphasize open palms while real world martial arts favor the closed fist?