Rich poor gap and number of children

Yesterday I was reading an article in the newspaper about some people struggling to make ends meet, and, all of them had at least two children, my initial sympathy vanished, wouldn't they have been so much better if they had say one child. You might say, who am I to family plan for then but one cannot complain of having to make ends meet when you have more expenses of your own doing, in fact I would like to add that you are making your other kid suffer as well.

The only way for the poor to move up from poverty is to have less kids, say, under all conditions being equal (education, ability, opportunity) each person earns 10, so if the poor guy with an earning of 5 has one kid and is able to get him/her to earn 10 and leaves him with his earning of 1 to make his total 10 + 1 = 11. The rich man has an earning of 50, he has three kids and is able to leave them an earning of 10 each, with their earning of 10, will get them each to 20. The disparity has come down from 50 - 5 = 45 to 20 -10 = 10, and that will improve if the next generation of the poor guy has one kid and the rich have 2 kids.

Agreed this is an over simplification, but the basic premise if correct, if poor people want to rise above poverty they must must have less kids, which in my opinion is not happening, thus the divide between the rich and poor will remain or actually widen.

The basic purpose of a human is to propagate, but what is the use of that propagation if you are not giving the best resources to your progeny to succeed. I see some people countering, hey, so poor people shouldn't have kids, well its up to them, all I am saying is they are not doing their kids any favour by bringing them into the world.