That could lead to an increase in the spread of STIs. I haven't crunched the numbers to support this hypothesis, but if men aren't worried about causing pregnancy they might forgo condoms altogether.

Why do people jump to this radical stuff rather than cheap, legal contraceptives and cheap, legal abortions? It's not a total solution but it's a lot better than, "Can't pay your rent? Get yourself sterilized!" and less likely to lead to a lawsuit when someone turns their life around and accuses the state of manipulation of the poor.