Proponents of the extension argue that the cameras cut side-impact collisions at traffic lights. Opponents argue that they increase rear-end collisions.
I'm not a big fan of them, but it seems to me that one of the reasons for that is that they exist in only a small minority of locations. Nobody wants them to be in every intersection (then you could definitely talk "big brother"), but the tiny number of intersections sporting them (or even fake cameras), means that we're not encouraging drivers to drive more safely, we're just asking them not to run red lights at a small number of intersections.
Unlike movable speed-traps, these cameras are kept at a single intersection and thus don't really provide periodic reinforcement that would be necessary to encourage people to obey red lights more carefully everywhere.
Perhaps if there were mobile systems that could be moved to any light within a jurisdiction or "blinds" that were set up up to provide the illusion that it was the case, drivers would be encouraged to take the lights more seriously. However, I'm quite certain that the current mechanism just provides some revenue enhancement for the local jurisdiction.