"I've never seen a dead body before. Not that close, and not one of ours. Do you get used to it?"
"When it's one of ours? No. With mundanes, it's easier. They hate it when we say that, but it's the truth. They kill and enslave and abuse each other with efficiency and enthusiasm. Why should we value their lives when they don't?"
-Bester's chillingly accurate point
We get the most comprehensive peek (outside of the novels) at what motivates Bester in this episode- family unity, a sense of superiority, and perceived necessity ("We may not be pretty," he says in an earlier episode, "but we're better than the alternatives."), which is not entirely without basis in fact.
The disregard for life demonstrated by the major players in this episode is disturbing because it is shared by "heroes" and "villains" alike. The spacing of the mundane accomplice was shocking because it was so matter-of-fact- but equally shocking were Zack's flippant remarks flagrantly condoning the murder of telepaths associated with the Psi Corps.
It may indeed be the case that Bester's more cynical view of teep/mundane relations is closer to the reality than the idealism of Dr. Franklin.