To secure his place as leader of the church Joseph had to isolate the role of prophet to just himself. In D&C 28:2 Joseph recorded a revelation that placed him as head of the church, and only the head could receive revelation for the church.
2 But, behold, verily, verily, I say unto thee, no one shall be appointed to receive commandments and revelations in this church excepting my servant Joseph Smith, Jun., for he receiveth them even as Moses. (D&C 28)
This has been interpreted by church leaders and members to mean NO ONE can receive a word from God except the head of the church. Which is contrary to how God works. God can call a prophet at any time he pleases and give to him His words. This is how it has always been done, except among Joseph’s churches. He in fact was the last prophet called directly by God. Their current church presidents receive an honorary title of prophet but this is contrary to how prophets have previously been called.
When Amos said:
7 Surely the Lord GOD will do nothing, but he revealeth his secret unto his servants the prophets. (Amos 3:7)
He was referring to prophets like himself – unordained, not priesthood appointed. Amos was a herdsmen when he received his call:
14 Then answered Amos, and said to Amaziah, I was no prophet, neither was I a prophet’s son; but I was an herdman, and a gatherer of sycomore fruit:
15 And the LORD took me as I followed the flock, and the LORD said unto me, Go, prophesy unto my people Israel. (Amos 7:14-15)
Such prophets as Amos have had no place in Joseph’s churches since the time of his death. It is not even an option, and this is a serious wound to how God works.