Call me crazy, but I think they're small because they're meant to be art, not porn. They're meant to be an idealistic high minded concept of beautiful, not a primal and animalistic beautiful, AKA not sexy. Women have always wanted men with big dicks just like men have always wanted women with big titties and fat asses, as proven by the numerous caveman venus figurines and ancient graffiti saying "I am Romanix Citizenus, and I have a big dick" accompanied by a doodle with a cock as big as the whole rest of his body.