You seem to be pulling presumptions from your posterior. That is not a reasonable argument it's just making shit up.
Your attitude is paternalistic in the extreme. Who are you or I or anybody else to try to force anybody to not do something that harms nobody but themselves? At least it could be that way. At the moment it hurts immeasurably across many lands because of prohibition. All that pain could be wiped out in a stroke leaving just the individual to deal with their own shit. It wouldn't even cost the NHS cos savings on drug enforcement cancel that out a gazillion times over. Yes the individual still has painful choices to make. They do anyway. The difference is in terms of how many innocents have to pay too.
Yeah maybe it does come across as paternalistic.
I think the law should be there to help people and support people, where at the moment it just seems to condemn them and ruin their lives more than the drug itself. So I meet you to an extent. I think full legalisation goes too far though, I personally would hate to see heroin legal. If it were I'd be too tempted to take it. As things stand, the difficulty in acquiring it means that my use of it can remain very minimal.
I would honestly leave the country if that stuff was legal. I'd have too much difficulty staying away from it.