Im on your side slipknot.
I've smoked my share of crack, and snorted my share of coke and heroin, and I found heroin to be much more enjoyable. I've never pawned or stolen anything or lied for cocaine or heroin, though I most certainly have for pot.
Some people, maybe even the majority of people who have used these drugs which many regard as the 'hardest' or most destructive have had bad experiences with them, but the drug is not to blame. In the end the blame lies with the user, no matter the substance.
I know I can get away with smoking pot several times a week, but I also know that frequent use of heroin can lead to physical withdrawals, and I know I don't have the money to support such an addiction thus I use it sparingly. Withdrawals by the way often take up to two weeks of frequent use to develop, maybe some people use several days in a row, wake up with no withdrawals and think they can use again. It's not like that, and if they continue to use it is their fault.
You're in control of what substances you put into your own body and how often you do so, it is really that simple. You control your own mind until you decide to cross the line and put the drug in control.
It goes for anything that can be used in excess, from meth to cough medicine with pot and alcohol in between.

Neither heroin nor cocaine are neurotoxic by the way, cocaine is cardiotoxic. It should also be noted that addiction itself is not harm, for example heroin addicts with high-paying jobs and the money to support their addictions can live as long as they would have normally.