User blog comment:Lemursrule/Bleach Fandom: The Real Enemy!?/@comment-5308032-20130216113145/@comment-5398287-20130216172237

Let me preface this with the fact that I very much agree with your post; people forget that there really is no truly good or 100% bad side in Bleach. The entire series is a big gray area, to be honest, and I'm glad to see someone provide a logical argument for their opinion.

But here's the thing. While the Shinigami are not entirely good in their actions, they have a job to do: protect the balance of the world. They do this by purifying Pluses to send them to SS and (occasionally) killing Rukongai souls to send them back to the world of the living. As long as there is an even distribution of souls in both SS and the Human world, balance is maintained. They also kill Hollows with their Zanpakutos to send those souls to SS. However, the Quincy represent a threat to this balance. When they kill a Hollow, that soul is gone forever; it doesn't go back to SS. If they had continued to do this, the soul balance would have been upset greatly. If the balance is upset, SS and the Human world will collide and merge, destroying all the life within each in the process. This is why the Shinigami had to destroy them; it was a necessary evil to save the world. However, I myself am not sure why they did not listen to the Quincy idea of protecting Humans without killing off Hollows. I think it may have something to do with some individuals in SS being corrupt (Mayuri Kurotsuchi comes to mind) but that's only a theory. Anyhow, I hoped this helped.