I don't have an issue with people doing drugs itself, I have an issue with the crime that goes along with it, depending on the drug.
Sure, it's not much good to lock people up purely for having the drug on them/taking it (if it's in quantities that are obviously for personal consumption, not for dealing), I agree with that sentiment.
But people who are on certain highly addictive drugs, that require them to constantly come up with money to finance their habit, usually turn to either prostitution (that's more women though, but not exclusively) or violent crime in order to finance it.
It starts out with petty crime like thieving, then gradually becomes stuff like robbing people and/or breaking into homes and shops etc. And if they're really itching and someone is trying to be a hero or hardman might get himself stabbed or killed, for not wanting to give up the 30 € he has on him and/or his mobile.
THAT is where my problem lies. I'm an ex junkie (opiates, and because we have a relatively liberal drug rehabilitation policy that allows easy access to a lot of substitution medicines I ultimately got hooked faster and worse on those than on the cheap, boshed up heroin I was buying from the Africans at the subway train station) but I was a comparitively high functioning one (I committed very little crime, and those I allegedly committed I targetted dealers, not random people) who held down full time jobs for years and was mostly able to hide it from his family.
But that's not the case for most. A lot of the people I was "friends" with (more like affiliated co-drug users, in reality, since most people are no longer capable of true friendship when the drug always ends up coming first) or knew are either dead from overdoses, in prison/multiple prison stints behind them, with very few who got clean like myself.
And the vast majority turned to one form of crime or another to finance their drug habit. This is not just true for opiates, but also for meth addicts (which is why it's a lie when American leftists claim that Blacks get harsher drug sentences with Crack, since Whites get punished approximately just as hard, except with the laws regarding Meth... just different strokes...) and certain other drugs.
You can offer as much help and substitution as you want, if people aren't themselves REALLY ready to quit it won't help. In fact many are on much higher doses than they actually need, so they can sell the extra capsules (ie Substitol, which is an opiate substitue prevalent here, that contains wax balls in a capsule that you can cook up, let it cool down so the wax settles on top, remove that, then filter it into a syringe the same you would with heroin) for extra money, creating even more addicts who're not in any program and who get hooked faster due to higher quality and then commit crime to be able to buy more.
I agree that the war on drugs is unlikely to be ever won, but is giving up and liberalizing and decriminalizing hard drugs really an option? I don't care about the marijuana, obviously.
Decent people with decent morals can and will turn into real rats (violent and treacherous), who simply don't give a <deleted>. Not to mention the impact on families, the burned bridges, the deaths, et cetera.
Yes, decriminalizing, liberalizing and maybe even legalizing brings in additional revenue for the state, and sometimes (but not always) drives organized drug traffickers out of business. But there's a cost attached here as well, and I'm not sure it ultimately adds up to less.