The two settlements, Jamestown and Plymouth, were so different because they were started for different reasons. Jamestown was established solely as a money-making venture. Many of the early inhabitants came from upper-class backgrounds and thought they would find gold and make easy money in Virginia. They had no higher purpose in coming, no thought of staying forever, and no idea of working for the common good.
The settlers at Plymouth, however, had a higher purpose. They came for two reasons. The first is the one we most often learn. These Protestants, who were persecuted in England for being Nonconformists (which meant rejecting the Church of England), wanted religious freedom. They also wanted to preserve their culture and remain English. Therefore, although they had settled in the Netherlands, which allowed them to worship freely, they also realized that their children were assimilating to Dutch culture, learning the language and customs, and drifting from their parents' ways. (They also feared the Spanish might take over the country and impose Catholicism.) The Plymouth settlers believed that in the New World they would be free to preserve both their religion and their culture.
The Plymouth settlers, therefore, had from the start the idea of putting down permanent roots and a sense of shared sacrifice.