If she's angry about the problems that come with newcomers, she can ask the govt or people to outlaw newcomers.
Otherwise ... No one occupies the high moral ground. Every newcomer, no matter how far back, changed forever what was there.
Edit: when I lived in San Diego in the seventies, it was all but impossible to get a permit for a new water hookup, effectively banning new homes and therefore new people. Your wife could start with that.