I'm not sure why government taxes should care whether someone has kids or not, it is your choice. If you can't afford to have kids, you probably shouldn't have kids. It's easy to be in a painful situation and come to a conclusion "Things should work this way because that would benefit me". There are other things the government should do, such as tax breaks for students, and people with student loans - fostering growt…
Because having kids benefits everyone. It's an integral societal good with a staggeringly high individual cost. There's a reason western European countries give such generous benefits to parents like lengthy maternity/paternity leaves.