The same can be said for pretty much any victimless crime. Victimless crimes, by default, are things that are considered "morally" wrong, and that's why they're illegal. Normal crimes are illegal because of other people being endangered or negatively impacted by the crimes, but the same isn't really true about victimless crimes, and quite often, by making the things illegal, you cause people to be endangered or negatively impacted by the crimes.

Which is more dangerous, going out and finding a drug dealer to buy pot from, or going to your local quik-e-mart and buying some like a pack of cigarettes? Similar cases can be made for prostitution and sex education (which, now, seems a bit off topic because it's not a crime, but I think it fits the theme of the conversation.)