Edit @Lonn: The using the whole animal/let it not go to waste thing is not a druid oath... a lot (maybe almost all) of druids take that philosophy, but there are those (like Pallena) who believe that nature is equipped to dispose of things naturally, which is why vultures and hyenas and worms and maggots exist...
I agree with you Shrowd that an official story/reason/explanation would be nice; but that's true for a lot of things in the game. Sometimes you just have to satisfied, and decide how your character would behave given the information you do have. I think you may be over-analyzing the alignment issue a bit - (again, my opinion only) the way your character views nature is probably more relevant to the issue than alignment.