Not trying to pile on you individually but this is an interesting line of thought in general, so continuing the thread here...
Let's say there are 10 nearby cities with drug addicts. Let's say 3 of them start running needle exchanges or other "drug friendly" policies.
By this logic, if those policies don't increase drug use, but do attract users, then maybe we just made 7 cities drug-free, and 3 cities into concentrated zones where social programs as well as law enforcement can be more targeted and more effective? If so, then very likely this will be a net-positive for the 10 cities as a whole, with neutral to slightly-worse outcomes for the target neighborhoods in the 3 cities running the programs.
Many programs/policies are not operated from a macro-enough perspective, or not optimizing for macro-level outcomes, or humans just aren't capable of macro-enough greater-good decision-making. If the 10-20 homeowners living directly next to the proposed needle exchange site can veto it, that might be better for them individually, but worse as a whole for the city/state/nation/world. See exhibit: NYC and proposals for new shelter sites.
On the other hand, seems like these sorts of debates always just end up becoming examples to prove out Churchill's "democracy is the worst form of government – except for all the others that have been tried" claim.