The mission's name is called, "Ice Cold Killa" that means Cj has an ice cold mentality. In the mission Cj states "Naw You f*cked up when you trusted me playa" Cj is a straight gangster without principles
That's because compared to all the other GTA protags, C.J. was a moron. You basically ran around in the streets like a hood rat blood shooting people with a ghetto mentality. Hmm.... he probably didn't even pass high school.