many people fear death by random, terrorist acts more than they fear death by any of the causes you mention because they feel they exert some control over those causes, but not over terrorist acts. many people believe terrorist acts are hard to understand, predict and avoid.

and, aside from that, many people really really really hate the notion that a terrorist, often from a foreign country, can kill people in their own territory, a place they consider "safe". people find this particularly disturbing because of the direct human malevolence involved. people are one of the scariest things people can face.

when we simply reduce these types of deaths into counts, we lose some of that human perspective and what makes people live their lives in fear and anger.