QUESTION: Why did such Hinayāna sages as Kāśyapa and Ānanda not propagate the Mahāyāna sutras?

ANSWER: First of all, they were incapable of preaching the Mahāyāna sutras. In the second place, there were no people with the capacity to understand and believe the Mahāyāna teaching. In the third place, they were not requested by the Buddha to do so. In the fourth place, the time had not come to propagate the Mahāyāna sutras.

Soya Nyūdō-dono-gari Gosho, A Letter to Lay Priest Lord Soya, Writings of Nichiren Shōnin, Doctrine 3, Pages 153.