Why do you think William Bradford mainly writes about the settlers as a whole, rather than as individuals?

One reason is that Bradford does not attribute the ultimate success of the colony to the actions of men. In Plymouth Plantation, he is far less interested in portraying the bravery or the hardiness of the Pilgrims than showing how the Pilgrims were guided by God, and succeeded because of his favor. As he says shortly after describing their landing at Plymouth, "what could now sustain them but the Spirit of God and His grace?" For him, the answer is clearly "nothing," and a major motive in writing his history of Plymouth is to demonstrate this belief. Bradford was also a leader of a small, tight-knit group of religious radicals. They came to New England to preserve their community, which had been under threat in England itself, and seemed to be losing its identity in their stay in the Netherlands. By not glorifying the individual (we might look to John Smith's autobiographical account of the settlement at Jamestown for an example of this kind of colonial writing) Bradford emphasizes the importance of this small, godly community that had been transplanted to what he portrays as such a hostile environment.