You seem to be confusing the unrealistic ideals on which Communism is based with the empirical results of every attempt that has been made to put those ideals into practice.
Marx did not intent or expect that trying to follow his ideals would lead to mass-murder and brutal oppression. He was, of course, very much mistaken.
While communism of Marx is far different than the law of consecration, the Book of Mormon is a critique against individualistic competitive materialism and supports a collectivist type of economic system. Not a forced one, but one where individuals use their free agency to make covenants to share God's wealth.
2 And it came to pass in the thirty and sixth year, the people were all converted unto the Lord, upon all the face of the land, both Nephites and Lamanites, and there were no contentions and disputations among them, and every man did deal justly one with another.
3 And they had all things common among them; therefore there were not rich and poor, bond and free, but they were all made free, and partakers of the heavenly gift. - 4 Nephi 2:2-3
4 And it came to pass that the thirty and seventh year passed away also, and there still continued to be peace in the land.
5 And there were great and marvelous works wrought by the disciples of Jesus, insomuch that they did heal the sick, and raise the dead, and cause the lame to walk, and the blind to receive their sight, and the deaf to hear; and all manner of miracles did they work among the children of men; and in nothing did they work miracles save it were in the name of Jesus.
6 And thus did the thirty and eighth year pass away, and also the thirty and ninth, and forty and first, and the forty and second, yea, even until forty and nine years had passed away, and also the fifty and first, and the fifty and second; yea, and even until fifty and nine years had passed away.
7 And the Lord did prosper them exceedingly in the land; yea, insomuch that they did build cities again where there had been cities burned.
8 Yea, even that great acity Zarahemla did they cause to be built again.
9 But there were many cities which had been sunk, and waters came up in the stead thereof; therefore these cities could not be renewed.
10 And now, behold, it came to pass that the people of Nephi did wax strong, and did multiply exceedingly fast, and became an exceedingly fair and delightsome people.
11 And they were married, and given in marriage, and were blessed according to the multitude of the promises which the Lord had made unto them.
12 And they did not walk any more after the performances and ordinances of the law of Moses; but they did walk after the commandments which they had received from their Lord and their God, continuing in fasting and prayer, and in meeting together oft both to pray and to hear the word of the Lord.
13 And it came to pass that there was no contention among all the people, in all the land; but there were mighty miracles wrought among the disciples of Jesus.
14 And it came to pass that the seventy and first year passed away, and also the seventy and second year, yea, and in fine, till the seventy and ninth year had passed away; yea, even an hundred years had passed away, and the disciples of Jesus, whom he had chosen, had all gone to the paradise of God, save it were the three who should tarry; and there were other disciples ordained in their stead; and also many of that generation had passed away.
15 And it came to pass that there was no contention in the land, because of the love of God which did dwell in the hearts of the people.
16 And there were no envyings, nor strifes, nor tumults, nor whoredoms, nor lyings, nor murders, nor any manner of lasciviousness; and surely there could not be a happier people among all the people who had been created by the hand of God.
17 There were no robbers, nor murderers, neither were there Lamanites, nor any manner of -ites; but they were in aone, the children of Christ, and heirs to the kingdom of God.
18 And how blessed were they! For the Lord did bless them in all their doings; yea, even they were blessed and prospered until an hundred and ten years had passed away; and the first generation from Christ had passed away, and there was no contention in all the land.
So at the zenith of Nephite civilization, they lived a collective economic system where all things were shared in common. Things would later change as they became really prosperous and some began to have pride and seek to prosper above the group:
22 And it came to pass that two hundred years had passed away; and the second generation had all passed away save it were a few.
23 And now I, Mormon, would that ye should know that the people had multiplied, insomuch that they were spread upon all the face of the land, and that they had become exceedingly arich, because of their prosperity in Christ.
24 And now, in this two hundred and first year there began to be among them those who were lifted up in apride, such as the wearing of costly apparel, and all manner of fine pearls, and of the fine things of the world.
25 And from that time forth they did have their goods and their substance no more acommon among them.
26 And they began to be divided into classes; and they began to build up achurches unto themselves to get bgain, and began to deny the true church of Christ.
27 And it came to pass that when two hundred and ten years had passed away there were many churches in the land; yea, there were many churches which professed to know the Christ, and yet they did adeny the more parts of his gospel, insomuch that they did receive all manner of wickedness, and did administer that which was sacred unto him to whom it had been bforbiddenbecause of unworthiness.
28 And this church did multiply exceedingly because of iniquity, and because of the power of Satan who did get hold upon their hearts.
The Book of Mormon, like the New Testament gospels is clear what riches above your basic needs should go to if you are a true follower of Christ:
17 Think of your brethren like unto yourselves, and be familiar with all and free with your substance, that they may be rich like unto you.
18 But before ye seek for riches, seek ye for the kingdom of God.
19 And after ye have obtained a hope in Christ ye shall obtain riches, if ye seek them; and ye will seek them for the intent to do good—to clothe the naked, and to feed the hungry, and to liberate the captive, and administer relief to the sick and the afflicted. Jacob 2:17-19
The Saints of the New Testament "The Church of Jesus Christ" had the same economic policy:
32 And the multitude of them that believed were of aone heart and of one soul: neither said any of them that bought of the things which he cpossessed was his own; but they had all things dcommon.
33 And with great power gave the apostles witness of the resurrection of the Lord Jesus: and great grace was upon them all.
34 Neither was there any among them that lacked: for as many as were possessors of lands or houses sold them, and brought the prices of the things that were sold,
35 And laid them down at the apostles’ feet: and distribution was made unto every man according as he had need. Acts 4:32-35
When God restored The Church of Jesus Christ of Latter Day Saints through the prophet Joseph Smith the same economic policy was implemented:
15 And it is my purpose to provide for my saints, for all things are mine.
16 But it must needs be done in mine own away; and behold this is the way that I, the Lord, have decreed to provide for my saints, that the poor shall be exalted, in that the rich are made low.
17 For the earth is full, and there is enough and to spare; yea, I prepared all things, and have given unto the children of men to be agents unto themselves.
18 Therefore, if any man shall take of the abundance which I have made, and impart not his portion, according to the law of my gospel, unto the poor and the needy, he shall, with the wicked, lift up his eyes in hell, being in torment. D&C 15-18
In a very symbolic name change to the city they had gathered to, after the latter day saints adopted the Lord's economic system, they changed the name from Commerce to Nauvoo which in Hebrew means "beautiful". And they built the most beautiful city in the American frontier. After the Mormons fled on their exodus they tried to implement this economic policy again but too many of them were too materialist. Brigham Young explained it something like this, a man would have three extra horses he didn't need but instead of giving them to those in need he'd rationalize well I may have more kids and they'll need the horses, etc. Given so many were too covetous, like the Israelites in Sinai, who were chastised and given a lesser law as a way to prepare them at a later date for the higher law, the Church implemented the 10% tithing and welfare fast the first of each month where you can give what your conscience guides as a way to prepare the Church for the future.
