If it's a "market" then why do they enforce "fair bets" and disallow actually participating in a market to prevent influence on the totally-not-gambling-bets? If it's a market I can go play there and maybe even win it completely if I'm that good. So can I go to Poly, make a bet on a market state and then go change that market to satisfy my bet, aka "predict" it successfully? No? Why? Oh, because it's not actually predicting, it's gambling, and fixing gambles is a bad sport. Poly and Kalshi are biggest hypocrites ever.
It's a market in the same way that poker and blackjack are "markets" on which cards are most likely to appear. You don't need to redefine what gambling is.