"Many such examples of slander are also found among Nichiren’s disciples and lay believers."

Thanks for your observations. Nichiren teaches, 

“They entirely look up to groups of icchantikas and rely on them as leaders and, reverencing slanderers against the Dharma, make them national teachers. Taking up the Classic Filial Piety of Confucius, they beat their parents’ heads and, while chanting the Lotus Sutra of Lord Shakya with their mouths, they go against the Master of teachings.” 

and

"For persons of the Tendai Lotus school to chant Namu-myoho-renge-kyo themselves and yet give their approval when others repeat the Nembutsu would be strange enough. Yet not only do they fail to remonstrate with them, but they criticize one who does confront the Nembutsu school, which is strange indeed!"

and

"Many such examples of slander are also found among Nichiren’s disciples and lay believers."

and

"Now you should make a great vow and pray for your next life. If you are disbelieving or slander the correct teaching even in the slightest, you will certainly fall into the great citadel of the hell of incessant suffering. Suppose there is a ship that sails on the open sea. Though the ship is stoutly built, if it is flooded by a leak, those on the ship are sure to drown together. Though the embankment between rice fields is firm, if there is an ant hole in it, then surely, in the long run, it will not remain full of water. Bail the seawater of slander and disbelief out of the ship of your life, and solidify the embankments of your faith. If a believer’s offense is slight, overlook it, and lead that person to obtain benefits. If it is serious, encourage him to strengthen his faith so that he can expiate the sin."

and

"In the same way, the renegade disciples say, “Though the priest Nichiren is our teacher, he is too forceful. We will spread the Lotus Sutra in a more peaceful way.” In so asserting, they are being as ridiculous as fireflies laughing at the sun and moon, an anthill belittling Mount Hua, wells and brooks despising the river and the ocean, or a magpie mocking a phoenix. Namu-myoho-renge-kyo."

continued...

and

"Daigaku and Uemon no Tayū had their prayers answered because they followed my advice. Hakiri seems to believe my teachings, but he ignored my suggestions about his lawsuit, and so I have been concerned about its progress. Some good seems to have come of it, perhaps because I warned him that he would lose unless he followed my advice. But because he did not listen to the extent I had hoped, the outcome has been less fruitful than he expected.

If lay believers and their teacher pray with differing minds, their prayers will be as futile as trying to kindle a fire on water. Even if they pray with one mind, their prayers will go unanswered if they have long made the error of attacking greater teachings with lesser ones. Eventually, both lay believers and their teacher will be ruined."

and

“If there are those who possess differing ideas concerning the three treasures, then truly you should know that these people can no longer hope to take refuge in, or rely upon, the three pure treasures. They will never gain benefit from any of the precepts, and in the end, they will fail to obtain the fruits of the voice-hearer, the cause-awakened one, or the bodhisattva.”

and

"In that age there will be evil monks who will steal this sutra and divide it into many parts, losing the color, scent, and flavor of the correct teaching that it contains. These evil men will read and recite this sutra, but they will ignore and put aside the profound and vital principles that the Thus Come One has expounded in it and replace them with ornate rhetoric and meaningless talk. They will tear off the first part of the sutra and stick it on at the end, tear off the end and put it at the beginning, put the end and the beginning in the middle and the middle at the beginning or the end. You must understand that these evil monks are the companions of the devil.”

Therefore, it is not difficult to understand that without a correct faith how one may develop a resistance to Nichiren's exemplary practice.

"Among my disciples, those who think themselves well versed in Buddhism are the ones who make errors. Namu-myoho-renge-kyo is the heart of the Lotus Sutra. It is like the soul of a person. To revere another teaching as its equal is to be like a consort who is married to two emperors, or who secretly commits adultery with a minister or a humble subject. It can only be a cause for disaster

and

"Now I, Nichiren, understand these things because of what I myself have undergone. But even if there are those among my disciples who understand them, they fear the accusations of the times; believing that their lives, which are as frail as dew, are in fact to be relied upon, they backslide, keep their beliefs hidden in their hearts, or behave in other such ways."

and

"But if any of Nichiren’s disciples disrupt the unity of many in body but one in mind, they would be like warriors who destroy their own castle from within."

and

"However, there is a difference if one chants the daimoku while acting against the intent of this sutra."

and

"Take these teachings to heart, and always remember that believers in the Lotus Sutra should absolutely be the last to abuse one another. All those who keep faith in the Lotus Sutra are most certainly Buddhas, and one who slanders a Buddha commits a grave offense."

and

"In the first five hundred years of the Former Day of the Law following the Buddha’s passing, only Hinayana teachings spread, while in the next five hundred years, provisional Mahayana teachings spread. The thousand years of the Middle Day of the Law saw the rise of the theoretical teaching. In the beginning of the Latter Day of the Law, only the essential teaching spreads, but even so, the theoretical teaching should not be discarded. Nowhere in the entire Lotus Sutra do we find a passage suggesting that we should discard the first fourteen chapters, which comprise the theoretical teaching. When we distinguish between the theoretical and the essential teachings on the basis of the threefold classification of the entire body of the Buddha’s teachings, the pre-Lotus Sutra teachings were to be spread in the Former Day, and the theoretical teaching, in the Middle Day, but the Latter Day is the time to propagate the essential teaching. In the present period the essential teaching is primary, while the theoretical teaching is subordinate. But those who therefore discard the latter, saying it is not the way to enlightenment, and believe only in the former, have not yet understood the doctrine of Nichiren’s true intention. Theirs is a completely distorted view.

This doctrine concerning the theoretical and essential teachings is not my own [but was expounded by the Buddha]. Those who would distort it can only be possessed by the heavenly devil, or Pāpīyas, and will topple others along with themselves into the great citadel of the hell of incessant suffering. How foolish they are! Teach this doctrine to others clearly as I have taught you these many years. Those who call themselves my disciples and practice the Lotus Sutra should all practice as I do. If they do, Shakyamuni, Many Treasures, Shakyamuni’s emanations throughout the ten directions, and the ten demon daughters will protect them. Yet, for all that, [some people associated with Ōta Jōmyō distort the teaching]. I cannot fathom what could be in their minds."