Because in the early days when foreigners came to China, they flew in, and they were curious, pointed and asked "Watt?", foreigners thought, they are from a hometown, and they don't even speak English. The Chinese responded by making gestures and clapping their hands as if they were flying. The Chinese nodded and said, "A chicken that can fly! If I rub it, the chicken will fly!" After that, the plane was taken over by the Chinese. Translated, eh, homophonic. There is no scientific basis. I wrote it myself