People might get the idea that they have a right to control their own body. They might think that they have a right to buy medical drugs without a perscription.
Then where will the Doctors and insurance companies be? Broke, that's where.
What will happen to all those lawyers. The prosecutors and defenders?
Oh, no. We can't let that happen. We must continue to destroy people's lives so we can have high paying jobs.
They do have that right. Just not in a community where irresponsible use of a drug results in harm of others in the community. This would apply to narcotics that when used irresponsibly, result in citizens that are a risk to others, or to antibiotics, that when used irresponsibly can result in creating immune bacteria that cannot be cured by simple antibiotics anymore, ect, ect.