Common, admittedly, was affiliated with the Chicago organization Four Corner Hustlers. The Corner is about experiences gained from desperate circumstances, and the struggle for survival by hustling. The corners are the intersections for the roads traveled on that path.
The world is unforgiving, and unsympathetic. Chicago's organizations began with the attempt to uplift and protect one another from the conditions imposed upon Blacks as the most hated group of peoples of the planet. To protect peace, and love, and get freedom from oppression. People assembled with each other at the corners.
Infiltrators, assisted and sabotaged the corners, now they're all at each others throats ("where struggle and greed fight").