Well... when someone's pain levels are stuck at 9 on a scale of 10 for long enough, anything that might bring the pain to an end can start to sound good, especially if it's something that other people are willing to treat as a serious problem deserving of some serious morphine. Most people don't have much experience with the effects of cancer--unless they've lived with someone who had it, for most people cancer's just something they've heard about or seen in a neighbor or distant relative. And cancer does have the (perhaps dubious) benefit of eventually coming to an end, one way or another.