GB and others I wanted to come back on the question of why society doesn't give financial value to people looking after their own children, who should pay for childcare etc.. (before I got distracted by the other wierdness on this thread).
Society doesn't generally and automatically pay people to look after their own children (or to have children in the first place) because it doesn't have to. People will undergo considerable personal cost to have children because they want to (or maybe less consciously their body wants to). It costs them money - expenses, foregone wages and freedom - but it gives them pleasure and fulfillment and they think it's worth it.
As you say government money isn't free money so it isn't obvious at all that taxpayers - low and high income - should pay to compensate all SAHPs.
What they should pay for is keeping families out of dire poverty, because all children deserve a decent upbringing, and ideally they should do it in a way that doesn't trap people in the 'safety net' forever but enables them to become financially independent again.
GB - you were saying (sorry can't find the post) that employers should take more of the burden, and that if employers weren't patriarchal there wouldn't be such a high cost to being a parent. I think this is true to a certain extent - employers overly penalising people taking years away, not being flexible, overly penalising pt work etc...
But there is no getting away from the fact that any time you are engaged in looking after your children you are not at work creating value for other people (and vice versa) and someone has to pay for that. And it goes on for 18 years - everyone thinks of maternity leave and the baby years, but it gets harder once you have school holidays, multiple social lives, homework help to deal with.
If employers had to give everyone lower hours, term time working etc... at the same take home salary it would cost them money - and everything would get more expensive (including the cost of public services) - it would end up with the same result as charging everyone a higher tax. There is no free money either way.
What I do think should happen is that dads should take more equal role in parenting, and employers be more flexible.
Of course there is always room to change policy and shift the balance of who pays for bringing up the next generation between employers (and therefore consumers) tax payers and parents. But I don't think there is a perfect solution with no trade offs.
'It takes a child to raise a village' sounds nice a fluffy, but subsistence villages where that happens are small minded, controlling places (they have to be to be because it's such a hard life). Villages don't raise children and encourage them to follow their dreams they do it so they can start working in the fields.