This draws a false dichotomy between "people use X" and "nobody uses X." There's actually a sliding scale of how many people use X. When a thing is illegal, fewer people will use it and the people who do use it will be at risk. If we thing a thing is important and that people should be able to use it, it's bad if that thing is illegal. There's a reason why people fought so hard decriminalize gay sex—not because laws against gay sex made it impossible, but because those laws were nevertheless really bad for gay people.