I don't think we have any active members right now who identify as Shintoists...as far as the appeal of earth-centered, naturalistic, ancestral, cultural, ethnic, etc. traditions - the reasonings should be rather universal. That could help if you come up a little short regarding response about Shinto traditions specifically.
Professor Sokyo Ono wrote at the end of his book (Shinto. 1962):
Shinto is a racial religion. It is inextricably interwoven with the fabric of Japanese customs and ways of thinking. ... But this does not mean that there is no concern in Shinto for the people and welfare of mankind ... People of all races and climes cannot but express gratitude to the spirits of the land and of nature, to their ancestors, to the benefactors of society and the state. In as far as they recognise this feeling within them, they cannot but understand the spirit of Shinto, and find in it an undeniable truth which supports and heightens man's highest values. Thus, while Shinto is a racial faith, it possesses a universality which can enrich the lives of all people everywhere.
In other words, Shinto is Paganism as practiced in Japan. Its appeal is the appeal of any form of Paganism: connection with the deities and other spirits and the enrichment of our lives. Living in Europe, I practice Hellenic Paganism; if I lived in Japan, I'd practice Shinto.