Why did Brigham Young only receive one revelation?
First of all review one account from Howard Coray of how Joseph Smith produced revelations.
Well, they could not find what they wanted and Joseph said to Thompson. “put the manuscript one side and take some paper and I will tell you what to write.” Bro. Thompson took some foolscap paper that was at his elbow and made himself ready for the business. I was seated probably 6 or 8 feet on Joseph's side, so that I could look almost squarely into Joseph's eye – I mean the side of his eye. Well, the Spirit of God descended upon him, and a measure of it upon me, insomuch that I could fully realize that God, or the Holy Ghost, was talking through him. I never, neither before or since, have felt as I did on that occasion. I felt so small and humble I could have freely kissed his feet. (The Words of Joseph Smith, p. 51)
It is also instructive to see how Brigham Young felt about the words that the Apostles would utter. This is from his April 1852 conference talk.
If you know what the calling of an Apostle is, and if there were ten thousand of them on the earth at the same time, you must know that the words of an Apostle who magnifies his calling are the words of the Almighty to the people all the time. He never need be called in question whether he revealed the mind of the Lord or not.
Section 136 of the Doctrine and Covenants was presented to the church as a revelation from Brigham Young. Brigham had been bothered by trying to manage the affairs of the church using the majority of the quorum of the twelve. The members of the quorum of the Twelve felt that a revelation was needed as specified in the D&C "The president of the church, who is also the president of the council, is appointed by revelation" (D&C 102:9) This revelation in January of 1847 didn't accomplish that purpose.
Writing D&C 136
From the Journal History we have the following which shows that 7 brethren met together for 4 hours, then the Twelve met for three hours and then Young and Richards finished writing the “revelation” at the Octagon building. So we have a total of 7-8 hours to write this Word and Will of the Lord which comprises 42 verses.
It might be interesting to remember that the Twelve with Brigham Young as their president had been leading the church about 2 ½ years. Brigham is desirous of re-organizing the first presidency, but it will not happen until the end of this year.
14 JAN 1847
Thusday, January 14, at 12:30 pm. Pres. Young met with Elders Ezra T. Benson, Orson Pratt, Wilford Woodruff, Geo A. Smith, Ezra T. Benson and Capt. Hosea Stout in council at Elder Kimball's. Pres Young proposed that letters be written to instruct brethren how to organize companies for emigration, and that Ezra T. Benson and Erastus Snow form an Emigration company. Number three, appoint a president of three, and captains of hundreds, fifties and tens, a clerk, and oversee them. Also that Orson Pratt and Wilford Woodruff organize another company. Number four, and that Amasa M. Lyman and George A. Smith organize a company Number Five.
Pres Young commenced to give the Word and Will of God concerning the emigration of the saints and those who journey with them. At 4:30 p.m. The council adjourned.
At seven, the Twelve met at Elder Benson's. Pres. Young continued to dictate the word and will of the Lord. Council adjourned at ten p.m., when Young retired with Dr. Richards to the Octagon and finished writing the same which is here inserted:
[Just the first 10 of 42 verses are included here]
1 The Word and Will of the Lord concerning the Camp of Israel in their journeyings to the West:
2 Let all the people of The Church of Jesus Christ of Latter-day Saints, and those who journey with them, be organized into companies, with a covenant and promise to keep all the commandments and statutes of the Lord our God.
3 Let the companies be organized with captains of hundreds, captains of fifties, and captains of tens, with a president and his two counselors at their head, under the direction of the Twelve Apostles.
4 And this shall be our covenant―that we will walk in all the ordinances of the Lord.
5 Let each company provide themselves with all the teams, wagons, provisions, clothing, and other necessaries for the journey, that they can.
6 When the companies are organized let them go to with their might, to prepare for those who are to tarry.
7 Let each company, with their captains and presidents, decide how many can go next spring; then choose out a sufficient number of able-bodied and expert men, to take teams, seeds, and farming utensils, to go as pioneers to prepare for putting in spring crops.
8 Let each company bear an equal proportion, according to the dividend of their property, in taking the poor, the widows, the fatherless, and the families of those who have gone into the army, that the cries of the widow and the fatherless come not up into the ears of the Lord against this people.
9 Let each company prepare houses, and fields for raising grain, for those who are to remain behind this season; and this is the will of the Lord concerning his people.
10 Let every man use all his influence and property to remove this people to the place where the Lord shall locate a stake of Zion.
Notice that about these same instructions were given about a year earlier.
Journal History of the Church
Friday, March 27 
. . .
When it was decided that the Saints would remove from Nauvoo, about twenty-five men were selected by the general council and called captain of hundreds, whose business it was severally to select one hundred families and see that they were prepared for a journey across the Rocky Mountains; afterwards the Captains of hundred selected their own captains of Fifties, and Tens, clerks, etc.
This discussion about D&C 136 is not to suggest that it isn't a worthy addition to our Doctrine and Covenants. It has a great deal of useful and important doctrine and principles that are worthy of our understanding and study. However, this wasn't produced in the same manner as Joseph. He would dictate directly the words of the Lord. I think that Brigham realized how hard it was to try and emulate the revelations of Joseph and so he didn't try again. Particularly after he had accomplished his goal of reorganizing the First Presidency at the end of the year 1847.
Brigham Young testifies that he is not the prophet
Times and Seasons:
Saints Bereft of Their Prophet.
Prophet Still at the Head of His Dispensation.
Brigham Young didn't feel comfortable with the title of prophet
"For the first time in my life, for the first time in your lives, for the first time in the kingdom of God in the 19th century, without a Prophet at our head . . . Heretofore you have had a prophet as the mouth of the Lord to speak to you. But he [Joseph Smith] has sealed his testimony with his blood, and now, for the first time, are you called to walk by faith, and not by sight. . . . You cannot fill the office of a prophet, seer and revelator: God must do this. You are like children without a father and sheep without a shepherd." August 8th, 1844 discourse (Complete Discourses of Brigham Young, pg 20)
Journal of Discourses, 6:319-320 (April 7, 1852)