Why are Japanese people non-religious?

I do not think it’s necessarily true that Japanese people are not religious. According to the Government of Japan’s Agency for Cultural Affairs, there are 3 main religions in Japan: Shinto, Buddhism, Christianity, and a fourth category they call “Other”. As of December 2013, there were over 180,000 Religious Juridical Persons.

A religious juridical person “means a religious organization that obtains juridical status through certification by a prefectural governor or the Minister of Education, Culture, Sports, Science and Technology”. I don’t know how this number of religious organizations per population compares to the number of religious organizations in the western world.