It is so simple. Because he walked the walk, didn't just talk the talk. That is why he is in the position to interpret the Lotus Sutra. Who are we to overide what Nichiren says? Have we knelt on the beach with the executioner's sword about to seperate our head from our body for the sake of the Lotus Sutra? I've never been struck across the face with the Fifth Volume of the Lotus Sutra, have you? Let get real my dear readers. if you want the same results as Nichiren, the same depth of enlightenment, there is no other way but to practice as he did; to have faith in the Lotus Sutra and the Eternal Buddha Shakyamuni as he did; to do shakabuku as he did.