Isaiah is condemning the accumulation of real estate. Those who “join house to house” are consolidating their land-holdings into a single tract, in the process evicting those who previously lived on the land. The sole owner is now alone because he has eliminated everyone else. Ludlow explains the legal context:
This practice violates the spirit of the Law of the Jubilee, the property law of ancient Israel, which states that “the land shall not be sold forever” (Lev. 25:23). Instead, land was to remain within families and clans as a perpetual inheritance. (See 1 Kings 21, in which Neboth refuses to sell his ancestral lands to King Ahab.) The hoarding of land described in verse 8 was in violation of this law, for when all property was purchased by a few wealthy individuals, there was no place for the original families to dwell. Having no homeland, they were forced to move to the cities or live on the property of the owner as indentured servants or slaves.
This question was a pressing social issue in Isaiah’s time. According to Norman K. Gottwald, professor at the Pacific School of Religion, Berkeley, California:
With Damascus and Assyria both weakened in the first half of the eighth century, first Jehoash and then Jeroboam II were able to reign over a peaceful and increasingly prosperous Israel, while a period of similar accomplishment was enjoyed by Judah under Amaziah and Uzziah. Agriculture and trade flourished. From the Book of Amos we learn, however, that the prosperity and national confidence were experienced chiefly at the summit of the society whereas the majority of peasants were in dire straits. No doubt taxation and corvée played a role, but the particular focus of Amos is on the massive shift in land tenure from traditionally guaranteed family holdings to privately amassed estates taken over by debt foreclosures on impoverished farmers. In short, as in Solomon’s united kingdom, the “wonders” of eighth-century Israel were concentrated in a privileged class who rose to their advantages by the systematic deprivation and disempowerment of the peasant majority.
Culture: Nephi quoted these Isaiah texts not only to stress their spiritual message but also to provide a social charter for his people. This passage articulates an ideal of economic egalitarianism for the Nephite community. Isaiah condemns the wealth derived through the acquisition of land that dispossesses other members of the community. Nephite society will attempt to establish Isaiah’s described economic ideal rather than the sharply hierarchical society he denounces.
Social egalitarianism versus economic stratification is one of the recurrent conflicts in Nephite history. While Nephi does not tell us that this is the reason for the text’s inclusion, the importance of the theme in the remainder of Nephite history highlights the fundamental nature of this principle in Nephite society. Isaiah’s implicit endorsement of egalitarianism was therefore doubtless one reason Nephi included it in his record. It is also likely, given the principle’s long-lasting importance, that Nephi also preached it and implemented it as a foundational social principle.