I wouldn't want to exclude them, I just don't want to spend (even more) money supporting their bad habits. It is a two-way street: they want more money? They have to take that in the form of drug treatment.

The libertarian in me don't want to waste money on them at all but I am not blind to the fact that their life wouldn't have been as miserable as it is if we didn't have a stupid war on drugs.

And since HN tends to lean anti-social: for the objectivists: most of us would don't want to get denied care because we look like a junkie during an emergency.