Why had the settlers begun to turn toward individualism in The Crucible?
After years under a theocracy, the settlers were literally oversaturated with the extreme rules of the settlement. The theocracy that existed within the settlement was one of repression. If anyone went against the rules, such person would not only be a criminal, but also a heathen for going against the heavenly rule. The settlers were starting to rebel. Parris and Proctor were quite aware of the cracks in the surface of this otherwise "God-fearing" society.
PARRIS: What, are we Quakers? We are not Quakers here yet, Mister Proctor. And you may tell that to your followers!
PROCTOR: My followers!
PARRIS: There is a party in this church; I am not blind; there is a faction and a party.
PROCTOR: Against you?
PUTNAM: Against him and all authority.
PROCTOR: Why, then I must find it and join it.
There is also a financial factor involved in this individualism. The rules from England had changed considerably, one being the revocation of the original royal charter. This meant that the lands and ownerships that originally belonged to people in the settlement, the land charters, were all null, cancelled. New land titles were not yet able to be obtained. Imagine the struggle to keep the lines well-divided and strictly set upon so that nobody tries to take away what is yours.
All of these factors made the overall sentiment of the community one which was rife with individualism and separatism. It was each man for his own and for what he owned. Moreover, this atmosphere also gave way to ambition and the want for more, as in the case of Parris and many other characters.
Slowly but surely the once obedient flock will start breaking with anything that does not directly benefit them and their families. This is why the land, among other things, was such a sought after objective in the everyday lives of the men and women in the community.