SGI asserts that Nichiren disparaged the Lotus Sutra. You be the judge

"Why do all the Buddhas in the entire universe throughout the past, present, and future protect especially the Lotus Sūtra? It is because the Lotus Sūtra is the parent, wet nurse, and master of Buddhas in the entire universe throughout the past, present, and future. They say that frogs feed, hearing the voice of their mothers; if they don’t hear the voice of their mothers, they will not feed and grow up. The Indian lizard called kṛkalāsa eats in the wind; it won't grow if there is no wind. A fish lives in the water, and a bird makes a nest in the tree. Likewise, Buddhas live in the Lotus Sūtra. As the moon's reflection resides in the water, Buddhas reside in the Lotus Sūtra. Therefore, you must remember that where there is no Lotus Sūtra, there are no Buddhas."- Written on 24th October 1280, at Mt. Minobu by Nichiren

Go to SGI Library and search "Lotus Sutra". Write out the 3000 sentences where Nichiren discusses the Lotus Sutra. How many can be interpreted as Nichiren disparaging the Lotus Sutra? ~ 2998 of the sentences are Nichiren praising the Lotus Sutra. 2 sentences might be construed as "disparaging" the Lotus Sutra if read out of context.