I know the teacher thing is a nice 'feel-good' example, but based on the experience of my own mother's colleagues, for many teachers in these low income areas, the paycheck is also all they care about.
For me, it wasn't just about a feel-good thing, I enjoyed being around and had the most fun time on a day to day basis when hanging out and working with the high school teachers. I met them all at a summer program, so it was probably the more engaged teachers. Also, the teachers were from the same demographics as the students, so it wasn't white savior type people, but people from the actual community.