In my opinion, the fact that it's so addictive makes it more of a candidate for legalisation or at least greater availability, not less. If you have a population of addicts who will do anything for a fix, and the only people who will supply it to them are hardened criminals who are also into prostitution, extortion, theft, etc. what do you think will happen?

And note that while you are arguing that we should legalize heroin, I'm not taking a position on that. I'm merely arguing (1) that legalization is not going to happen politically so you shouldn't weigh down the marijuana legislation with this, and (2) that heroin is intrinsically devastating even when you remove the drug dealers, etc. Point #1 is based on my hunch, but I doubt many would disagree, and point #2 is based on my experience. Do you have evidence or experience that contradicts mine, or are you just speaking hypothetically?

Nice. Maybe try leading with that next time, instead of "Heroin is a wheelbarrow full of rockets." or something, hey? :)

I'm not arguing point #1 - I'm arguing that your point #2 is flawed. Your experience likely biases you in that direction, since you will have seen the absolute worst cases of addiction, instead of someone like a lawyer or executive who can afford to have a heroin habit without it bankrupting them, or who isn't addicted.