For the sake of exploring the issue further, I'll play devil's advocate.
No doubt many people, especially young people, are going to act irresponsible. However, if we are to not only provide them with a free birth control but also make it readily available to them (free home delivery for instance), would the birth rate not drop? I mean lets be honest, a big portion of the population was a mistake. They were not what you would consider a "planned pregnancy".
BC is basically free now for many yet they still don't use it. I have my doubts that delivering it to the house would suddenly result in people taking a pill every day.
Yes, there will always be this issue. However, we have Roe vs. Wade. Abortions of certain criteria is deemed legal by the highest court in the land. There are many statistics out there that point to abortion curving the crime rate among other things. Is it a stretch to say that subsiding abortions would be a bad thing from a society standpoint?
The natural chink in the armor against this would be that those who disagree with abortion on grounds of morality would not want their tax dollars to go towards such practices. However, these are also mostly the same people who b**** about having to pay for the single mother and that child for the next 18-22 years depending on whether they go to college. Not to mention the legal/jail fees if they go that route which statistics say they are most probable to travel.
RvW made abortion legal at the federal level based on the notion of privacy. Stretching that to say they should be tax payer funded doesn't fall within the RvW finding.
Yes, that is an another aspect of this argument, albeit to a lesser extent. They would say preventative medicine (gym fees, fresh fruit/vegetables, etc) is small price to pay for an obese person. Most obese people have trouble getting health insurance because of their preexisting medical conditions. If they don't qualify, they will be on either Medicare or Medicaid. If they do qualify for their employer's health insurance, they inevitably raise everyone else's rates. It is no secret that obese people would have astronomical medical bills compared to fit people.
In short, although it goes against all of our preconceived notions personal freedom/responsibility and small government values, it would actually probably save everybody a good bit of money and in the end reduce government spending (and possibly, although admittedly wishful thinking, reduce the overall size of government as well).