The "sin tax" is a pretty common way to profit from behavior you would like to curb as a government. I actually think it's a good way to handle the situation. Rather than force your citizens to do thinks "underground" and risk their safety engaging in business with possibly unscrupulous characters, they just have to pay insane taxes. This also probably helps the losers a bit, as they can at least get a decent tax break for a run of bad luck. In the US, some states have some pretty crazy sin taxes on alcohol and tobacco that make it difficult for some people to engage in those activities.