Why Nichiren never advocated the building of Buddhist halls or Pagodas (temples or SGI Kaikans)?

"I DO not build Buddhist halls or pagodas, I do not carry out almsgiving. The only thing I hold precious is my life, and this I have offered to the Lotus Sutra.

The Buddhas of the three existences of past, present, and future, when they were still ordinary mortals, all offered their lives to the Lotus Sutra and thus were able to become Buddhas.

For this reason, the names of all the various Buddhas are prefixed by the word namu. Namu is a word of the language of India, and in this country it means “to dedicate one’s life.” Explaining the term “to dedicate one’s life,” T’ien-t’ai says it means “to single-mindedly dedicate one’s life.” By offering their lives to the Lotus Sutra, they became Buddhas. And now I, Nichiren, am offering my life to the Lotus Sutra . . ." -- On Namu  SGI members...