Why is it insane?
Some woman who is 8 months pregnant comes to the US on a tourist visa and gives birth, then goes home with the baby. And then somehow that kid gets automatic US citizenship. And it applies even if the mother is not even legally allowed in the country. And you think that is not insane?
I'm not him, but it creates some perverse incentives (like chinese billionaires who pay american surrogates to get implanted with dozens of their kids who get american citizenship).
https://fortune.com/article/chinese-billionaire-xu-bo-father... might be an outlier, but it's still weird, especially since the US is the only country that has this.