I'm trying to understand what the criticism is here, because the example seems to support the point that these are meant to be a way of learning the future, not oppose it. I thought the whole point was that yes, people with inside knowledge will bet large sums of money on things they expect to happen, and that's what makes the prediction useful. The market is meant to incentivize people who know things to act on them in a way that makes them known.
If I knew someone wanted me dead, of course I would want a prediction market on it, and if the odds suddenly shifted dramatically in favor of my death, I would use that as a trigger for whatever defense strategies I had in place. Someone has really good reason to bet a lot of money on the prospect that I'm about to die. It's probably someone who knows of an active plot in motion to try to kill me! The sooner I can find out about that, the better. I would much rather give them an incentive to make that known somewhat earlier than wait.
I feel like there must be some big piece of this puzzle that I'm missing that makes it so these cannot operate the way I imagine them, but I haven't heard anyone explaining what it is. Someone fill me in on what I'm missing here?