I guess the GP's suggestion is to let people think twice before getting any? Children are expensive without this tax but most people don't think 1 second about that because it is somehow a right to have them so the state will provide (and in many countries here, indeed they will). If you can clearly see that you and your better half will never be able to support them until they are 18 (which goes for many people already, without any ridiculous taxation), you might think twice about having any at all?