At the time of the initial diagnosis wouldn't it have been obvious to Steve Jobs' doctors that the surgery would be hopeless, and that surgery would only inflict suffering and additional trauma to weaken an already sick person?
The way I have seen medicine (including veterinary that killed a cat of mine who was too weak to undergo surgery) applied is: aggressively. And, I don't see the bigger picture taken into account. In other words, if there is something to treat, just do it. Nevermind weighing adverse effects against benefits, nevermind the bigger picture, e.g. the body is too weak to withstand some assaults. Nevermind how advanced a cancer is. Just treat, treat, treat. Short term, tunnel vision, and profit making.
But then again, I err on the side of cautious and cynical. People really need to do as much homework as they can to try to know best how to weigh risks and benefits, and to understand their situation as best as they can in order to know when it's wise to refuse treatment.