Why do shots not illuminate their surroundings as they pass by, or the subsequnet impact explosions cause a nice glow emanating from the area of effect?

This would be a nice (optional) feature that could enhance the immersion.

It would be nice, but I'm fairly certain it would require a major overhaul of the graphics engine, and would also raise the minimum system requirements up a fair bit. All in all, not worth the costs to implement, IMO.

I suppose it would enhance immersion, but having each shot emit light, and each explosion emit light... That would put a fairly large load on graphics processors.