I think this is a fundamental misunderstanding of leftism. It's not that smoking crack is "cool," it's that the person smoking crack is a human being, deserving of dignity, who doesn't deserve to be thrown in prison. Of course that person shouldn't be allowed to smoke crack in an indoor public place, but is the solution really to take away all their freedom? I certainly don't think so.
I believe one case of this I saw this year (which was in the UK, and actually did result in them being arrested) had a bunch of people claim the specific subway-crack-smoking guy was both cool and being oppressed, and then it made the news and he turned out to be a domestic abuser. Not the most recent time I've seen this argument though - that would be yesterday, about Philadelphia I think.
People who do drugs in an enclosed space in public are doing an antisocial act and as such are the type of people willing to do other antisocial acts. It's different from simply being homeless.
That's a weird thing to call cool and whoever was saying that was cool was wrong, of course.
If someone is a domestic abuser who smokes crack on the subway, I think they should go to prison for domestic abuse and be kicked off the subway for smoking crack on the subway.
I do hate that people smoke on the Philadelphia subway, although it's mostly cigarettes and not crack in my experience. I think those people should be kicked off the subway. I just don't think that's the sort of thing someone she ould go to jail for.