There are two kinds of hybrid buyers: people that want it for the feature itself but packaged into a normal car, and people that want the feature but also want the car to say, "look at me, I'm driving a hybrid!" Cars like the Civic Hybrid, upcoming Accord Hybrid, Lexus RX400h, etc, serve the first group. You can't really spot a Civic Hybrid except for its different grille and the badge on the trunk. The Prius serves the second, because pretty much everyone either knows what it is or sees it and thinks it looks like some kind of eco-pod.