Japanese are no good at making engines, which isn't their fault, the law limits engines to 299HP over there.
Anyway...the reason the Skyline is winning is because most people here only know what they've seen in movies and videogames, additionally, many of them don't know the performance Corvette is classified as Z06, and just vote Skyline by default. The 1990s series Skyline is a great car, if you live in Japan.