A life is a life

A friend of mine recently watched Phone booth and came up with a question which I was surprised I did not think of when I watched this movie. Why did the pizza guy and the pimp have to die? So they just died so that this guy can be morally corrected? Isn't there any value for their lives?

The more disturbing fact was that it did not seem to affect me. Sure the pizza guy was probably just in the wrong place at the wrong time but the Pimp was murdered in cold blood and it didn't really strike at the heart because of what he does and what he represents.

Is that how we are tuned to be? We value a life of a saint and an achiever more than that of a violent offender or just someone insignificant. Doesn't that seem rather inhumane? Isn't a life still a life?

A related quote from the lord of the rings after the felling of an 'evil' soldier:
Faramir: [from the Extended Edition] The enemy? His sense of duty was no less than yours, I deem. You wonder what his name is, where he comes from, and if he really was evil at heart. What lies or threats led him on this long march from home, and would he not rather have stayed there... in peace? War will make corpses of us all.