I asked this yesterday but worded it poorly. As a result, the conversation got off-topic. If you want to read that discussion, look it up in my questions - they are free ranging and public as nature intended.
All vice crimes should be legal. Prohibition has been proven a failure. Legalizing drugs, prostitution, and gambling would save billions on enforcement and reap huge tax income. It would also allow for regulation of these existing industries, making them safer for everyone involved. Therefore, the only remaining reason to outlaw vice crimes is: they are immoral.
Why should the government be legislating morality when it’s a parent’s job to teach morals to their children?