User blog comment:Suparockr/List of Plotholes throughout the series/@comment-166.82.245.89-20120719070005/@comment-1679409-20120719075224

Regarding the kid:

Well, first of all, he's apparently the only child of any species Shepard has EVER seen. The destruction of something that's one of a kind can be quite devastating.

But in all seriousness, I think he represents an actual face on the destruction that is occurring, destruction that many are too weak to withstand. Shepard is one of the few, if not the only one, that fight for those like the boy. He also could represent the future and seeing him die after a brief glimmer of hope is like seeing the future die. So, the boy is more than a boy; he's a symbol.

Additionally, he's not the only one Shepard thinks about. if you listen during Shepard's dreams, you can hear the voices of dead squadmates like Legion, Thane, and Kaidan.