Q: But some argue that Nichiren Daishonin should have openly stated in that Gosho that he inscribed the Dai-Gohonzon, making its existence widely known!
A: This argument is based on setting a condition on what Nichiren Daishonin should have done after inscribing the Dai-Gohonzon. There are several important reasons why the Gosho does not specifically mentions the Dai-Gohonzon:

For Whom the Dai-Gohonzon Was Inscribed
The Dai-Gohonzon was not inscribed for Gosho recipients, but for the future generations of believers yet to appear at the coming stages of the global Kosen-Rufu movement. For this reason, revealing it in a letter at the time of its inscription would have been completely irrelevant to the daily life and local circumstances of any recipient of the Gosho.

The Validity of All Gohonzon
The idea that a Gohonzon is "valid" only with a letter from the Daishonin (concerning its inscription) undermines the validity of all Gohonzons which were not accompanied by a special letter of endorsement. In addition to individual Gohonzons, Nichiren inscribed “general” Gohonzons, (called also Maha Mandalas or Dai-Honzon), and none of them was accompanied by a special Gosho about its inscription. 

For example, there is no letter of endorsement to the general Dai-Gohonzon known as the Mannen Kudo Dai-Honzon, which is enshrined today at Hota MyoHonji temple (also referred to as Dai-Honzon for the Security of the Nation). Lack of a letter of confirmation about its inscription does not indicate that this particular DaiHonzon was not inscribed by the Daishonin, or that it is somehow invalid.

Security and Protection
The DaiGohonzon was inscribed in 1279 in an intense atmosphere of hostility and aggression against Nichiren’s disciples, culminating in the execution of three followers from Atsuhara. The Daishonin’s first concern was the security of his followers and the protection of the transmission of his doctrines. There are many passages in the Gosho in which Nichiren Daishonin warns his disciples not to reveal important doctrines (and in particular, the Gohonzon), but to keep it secret. This cautious approach was a manifestation of his wisdom to ensure the survival of the teachings. It was also his compassion and care for the protection and security of his followers. 

This work has been compiled by individual SGI members and is solely our personal opinion, based on years of practice and study.