So you dont think that the encounter would be more fun if you were actually competing for the kill in a real way? For example Auto PvP flagging when you attack them. Or through a contribution point system? You honestly think its more fun to just get one shotted when one player outside your group from EITHER faction attacks the mobs?
I remember SWG used to have it so the party that did the most damage would get credit for a kill.
They don't have that in SWTOR instead they have it so NPCS/MOBS get tagged by whoever hits them first & The one-shot kill for NP is obviously to keep multiple raids from joining forces to down it easier.
This thread/topic just proves yet again that if people can find a way to exploit a MMO to grief other players they will use it.