Joyce's death - a middle finger
Many Jigsaw-apologetic fans were annoyed at Joyce's death, since they thought it made Jigsaw so evil. I think the brutaliy of her death was deliberate from the filmmakers, as if to say "Jigsaw is the VILLAIN, you idiots. Does it take something this brutal and unfair for you to realize that? After all these movies?"
The fact that Jigsaw had his own bizarre sense of morality (which he passed on to Hoffman) doesn't alter the fact that he's the villain. All evil people pretend to themselves that they're the good guys, and rationalize their actions and stances. All mass murderers in the real world have done this too. As Ayn Rand said: "No man can survive the moment of pronouncing himself irredeemably evil. Should he do it, his next moment is insanity or suicide."