Many people have taken issue with the fact that despite Bobby being the one who is being tested, his wife dies despite his trying his hardest to save her and his friends. Then it occurred to me: in Saw V, Jigsaw mentions that he finds taking credit for someone else's work to be distasteful, especially when that work is inferior to his own. He was referring to Hoffman at the time, but the same basic principle can be applied to Bobby: Bobby was posing as a Jigsaw victim, thus imitating the other victims. He made up a poorly-conceived trap, when it's fairly obvious to anyone with medical knowledge (such as Dr. Gordon) that the pectoral muscles aren't strong enough to support the weight of the human body. Thus, it would make sense that Bobby is punished the harshest by having to watch his friends and wife die. It's no less inexcusable, but it makes more sense.
Not exactly. Body modifiers have actually done the body suspension and succeeded doing so. Bobby just needed to put them in deeper to succeed. Of course, he didn't have to impale them into himself; he could've used them as stirrups or put them under his armpits.
Except it's apparently well-known by that point that Jigsaw and his various apprentices and Boxed Crook patsies monitor the trap victims remotely. The people in Bobby's support group have probably mentioned cameras being present, or tapes and screens offering messages that demonstrated that they were being watched. So out-and-out cheating his way through a trap probably didn't seem like a viable strategy.
Most of the traps here are just plain Torture Porn, and lacked the psychological effect that the traps in the previous movies had. In short, it's just a really meaningless and excessively gory show that only satisfies those who expected that of Saw. Just another criticism of the movie? That's when you realize Bobby, is a greedy, lying writer who exploited the Jigsaw traps and ignored the suffering the victims went through just for money and fame. It's like Jigsaw is giving Bobby exactly what he expected of the traps...
A lot of people were bugged because of Jill's strong badassness pretty much was undone by Saw 3D. The problem is one has to look into it a lot more closely. In the previous movie, Jill was able to get the drop on Hoffman because he was sitting down and was temporary distracted by his note to Amanda. Jill was able to pretty much own Hoffman with this info and rigged the chair that Hoffman was sitting in. The brilliance comes when you realized Jill is a trained doctor, and isn't someone who clearly is not trained as a fighter. Hoffman is also overall stronger and bigger than her. Jill was hoping for Hoffman's death because she knew that she only had one shot with the Reverse Bear Trap 2.0 and knew that Hoffman would come and kill her, if he lived which is why she went to the police for help.
The ending seems to be the ultimate repudiation of Jigsaw's philosophy. If there's anyone throughout the series who has shown both the will and drive to live, it's Hoffman... and yet, he's left to die without any way to escape, not because of every single crime he's committed, but because he killed Jill, John's ex-wife. Combined with everything John does to people he personally disagreed with throughout the rest of the series, it proves conclusively that despite everything he claims, John is really just a bitter, angry man lashing out at the world and adding some window dressing so he can think of himself as a good person.
In fairness, John did give Hoffman a chance, and as you said, Hoffman did a LOT of stuff after John died beyond only killing Jill that was all just murder. To wit: 1) He directly messes with Amanda's test. While it's possible she might have been mentally unstable enough to shoot Lynn even without it, the letter he left her definitely sealed her fate, and indirectly sealed John's fate too. John, Amanda, and Lynn's deaths can essentially be traced back to Hoffman's letter forcing Amanda into shooting Lynn. 2) Later, Hoffman indirectly murders Strahm to frame him in the fifth film, then directly murders Perez, Erickson and Sachi to cover up his involvement with Jigsaw when they find Hoffman's voice on the Jigsaw tape in the sixth film. 3) And then Hoffman spends this film getting to Jill to kill her, while also killing Gibson, his partners and multiple other cops. He even murders the hapless Dr. Heffner solely because he was in the wrong place at the wrong time. John appreciates the will to live, but he has stated very clearly that he despises murderers, and by the time the film ends, Hoffman has directly/indirectly murdered multiple people solely to keep his identity as a Jigsaw apprentice secret, people who were just doing their jobs and had no reason to be tested, let alone murdered. John was willing to test Amanda a second time and forgive her when she started murdering people in her own traps if she passed another test. Hoffman got even more leniency. Not only was he never directly tested by John himself, but based on events, the only reason Dr. Gordon went after Hoffman is because the latter crossed the line by murdering Jill. Based on that, Hoffman WOULD have been allowed to live and not face the price (other than being hunted by police) if he hadn't murdered Jill. He'd have never been punished for his other murders. That's probably the most lenient we've ever seen John be with a man who has crossed the line multiple times into being a murderer.
Although many fans and viewers have complained about it (especially because of Joyce's death), Bobby being the only survivor of his game instead of dying in one like his staff, best friend and wife is actually a very fitting punishment with thought put into it. He's now a true Jigsaw survivor, at the cost of his closest people and with all the real physical and emotional trauma that comes from the experience. However, this time he has nobody to talk to about it without it somehow coming out that he previously made things up. Bobby's punishment can be summed up as being tied in his own lies and forced to go through that trauma in his mind for the rest of his life, which is more karmic for him than simply dying.
