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?

That was the joke ;)