There are dozens of pro bono clinics in the Bay Area and around the state that provide advice and legal assistance to low-income Californians. Volunteers (law students and lawyers) are critical to their mission. Check out www.californiaprobono.org. BTW, I agree with your sentiment. The very translation of the term "pro bono publico" from its Latin precludes work for for-profit enterprises, IMO.
I have a handful of students who want to be patent lawyers. Should I make them work on death penalty or civil rights cases?