Might as well derivate it from existing casino's roulette games, it's not like anyone betting on these are subject experts.
It's pure greed and fomo, sprinkled with a bit of cheating and corruption.
Someone who is a "subject matter expert" (and given how specific many of these predictions are, being an expert usually means you are an insider with non-public information) can indeed make money as long as a bunch of idiots with worse information place bets thinking they know the outcome. This is considered to be a crime when done with other securities.
Interested if you believe insider trading of stocks should be legal - aren't insiders just providing the market with more information about that stock?
EDIT: I suppose I also need to be able to purchase the “shares” in the “market”