Reducto ad absurdum doesn't work here. You have to show that there's a desire and a rationale for going from limiting betting markets like Kalshi and limiting "investment" markets, which you haven't done. What you have left is a salty quip.

There's an obvious opportunity to use insider information or insider influence to create a particular outcome on Kalshi. Like I could trade on the likelihood of a power outage in my city tomorrow or the next day and then in order to make good on the "trade" I could just drive a vehicle into the substation. Or I could do something more insidious. But the fact that my incentives are aligned by Kalshi with me blowing up a power substation means that Kalshi is a net negative even though individuals could make money from it.

There's a difference between betting on the outcome of an event and investing in a company, although companies like Kalshi and Polymarket like to try to erase that difference. Investments are all notionally conditioned on a company meeting performance goals, and that incentive is aligned with the desire of company employees to also meet performance goals. Companies also generally align around some kind of useful output like washing machines or clothing which are beneficial in some way. What is useful about betting on the color of the sky at sunset in Lisbon on September 28th?

You are apparently very happy with a market that is defined by an economist who views it as you view the prediction* market.

Prediction markets are useful in their own right because they help people plan with information independent of themselves and more accurate and less biased than other sources. That is very similar to a market allocating a societies future allocations through rewarding holding of past investments. Both actually have many of the same problems and elimination of either can not prevent insider trading on information or significant resources being wasted on zero sum game aspects or faults in how such simple systems of reward function layers allocate as well.

(If you plan to propose to a partner in September might it not be helpful to have an opinion about the night of the 28th? Is that more or less important than the OTC penny stock for a probably defunct mine that possibly has copper? But why not pick equivalent strong points. If you are planning purchase like a next auto might you find future energy market related bets helpful to estimating long term risks for your choice?)

*typo