Essentially you're saying you should only be wealthy to have kids.
I am not saying those without a certain level of wealth should not have kids but it should be a consideration. Money is time. Time is money. Why have a child if you are going to be working all the time and have no time to foster it? Why have one if you can't even afford to take care of yourself? Say my body doesn't work so I can't have children... if I want to adopt I have to go through screenings -- financial and otherwise to judge if I could provide for a child. Just because someone has a working body, I don't think they should be exempt from a certain amount of thought into the responsibility before the decision to have one.