Some variation of this inevitably comes up when discussing men's right to opt out of parenthood (financial abortion).

The logic is that men should be forced to pay as much as they can, regardless of what it does to their standard of living, to defray the costs of a kid and save the taxpayers money.

But I've never heard these people complain about the far greater sums we already spend on other people's kids: public education, public health, subsidized meals and daycare, etc. And on top of that we don't have a special parent tax to ensure most of these burdens fall on parents, indeed we have special and significant tax credits for parents such that nonparents end up paying more to raise those kids per person.

That hardly seems fair.

Also there are no restrictions on women who choose to go to a sperm bank or get pregnant with a man in jail, etc, where it's a known fact that won't have sufficient support.

Why do you think there's this discrepancy?

Edit: many people seem to be missing the point.

The question isn't "should we have public funding for any kind of social program ever."

It's "why are we ok funding the vast majority of parents with public funds but if the sperm donor wants to opt out suddenly we become a nation of bootstrap pullers and insist everyone bear the sole financial burden for their choices".

Yes public education is good, but why give tax breaks to parents while complaining about how unfair it would be for the state to cover "deadbeats" who shouldn't have had sex if they weren't prepared to fully covered the cost of a child they didn't want.