That may just mean you don’t understand the regulations and legal definitions involved. Shares of stock are portions of a company entitling the owner to dividends and possibly influence over company direction. Do shares on Kalshi represent a portion of a company and entitle you to a dividend?
No. So the line remains clear: You are allowed to trade stock as long as you follow the stock trading rules. You are not allowed to trade “Kalshi market shares” unless the rules change. You can say that they should change, but there’s no confusion about what is stock and what is illegal gambling.
Kalshi could perhaps try to list their company on the stock exhange and have the market shares become actual stock somehow, but they’d quickly run afoul of the stock trading rules if they tried to give larger dividends to some shareholders than others based on which markets they’d invested in. It would become an impossible headache, which is why they won’t do it.