This is exactly the marginalization he was talking about. Some of the smartest people I know love hard drugs and are very successful, are they throwing their life away because they use on a regular basis?
Maybe you are only talking about the outright stoners that just get high every day, but are they really any different to the other lazy people that don't work? Not doing anything ever is generally what I would consider to be throwing your life away.
I don't think drug use has much to do with throwing your life away, apart from the depression that comes from being marginalized. People that wish to throw their life away will do so with or without drugs.
If we treated addicts the same way we treated someone with any other mental or physical ailment, it would make it so much easier for them to actually function in society without "getting clean". Which might actually help a few of the ones who want to get clean, because from what I understand, it is much easier to kick a habit when you have more going for you, like a career and social life.
Just my two cents, from anecdotal evidence knowing drug users in a few different circumstances. Never been a user myself.
Where do you live?
There's a myriad of state and federally funded programs here in the US that help people get treatment for a nominal fee or in many cases for free. Not sure how much more compassionate you can be when you're giving people a free alternative to get clean.
Also, if you've never had an addict for a friend or a relative, then you'll never know it doesn't matter how compassionate you are to them, if they want to use and continue to throw their life away - they will. They have to be willing to help themselves first. No amount of free clinics, health care or compassion will combat that.