While Mormon describes the church as "general throughout the land" this is given as a marker of success. It is meant to lead us to believe that there was tremendous and universal success in preaching the gospel. It is certain that there was success, but subsequent events will show that it was surely not universal. The term "general" does not tell us that it was universal, and does allow for those who continued in unbelief. At this point, Mormon's purpose is not to describe accurately the social conditions, but to continue the contrast between the Ammonihahite Nehors and the gospel that is victorious over that threat (for the moment).
We see the continuation of Mormon's theme of victory over the Nehorites in the statement that "there was no inequality among them." This is again directed at the heart of Nehorite doctrine, that has always espoused social and economic disparity. The egalitarian ideal is uniquely Nephite.