Disaffected Christians in both the Old World and the New had the option of leaving Christianity completely for a competing pagan religion. An expansion of wealth was associated with trade, which historically brought the Nephites into contact with outside cultures, usually marked by apparently desirable social hierarchies. (See Alma, Part 1: Context, Chapter 1, “Historical Background of the Book of Alma.”)
Rather, the sacrament was being given to the unworthy, communicating that the new churches of the third century were developing unorthodox practices like those in the Old World. As the Nephite people expanded to cover the face of the land, this geographic spread would have had the same consequences as geographic diffusion in the Old World, leading to divisions and differences in their understanding of the gospel.
Chronology: Two hundred and ten years in the Nephite count would be A.D. 204 in our calendar.