Perhaps you'd like to become acquainted with addiction[1] and substance dependence[2]. They are real issues that people (those who you call criminally selfish) have to deal with, (generally) alone.
Due to societal attitudes towards drug use and the overly harsh treatment of users by the criminal justice system, people suffering from addiction often do not receive the medical and psychological attention they need. In a better world we'd be willing/able to provide that, but we aren't there yet.
People start doing drugs for many different reasons, but some people can't handle their crack. An addict can be a threat to themselves and/or others, not because they are "bad" or "selfish", but because they are mentally ill. Addicts need rehab, not punishment.
[1]: http://en.wikipedia.org/wiki/Addiction [2]: http://en.wikipedia.org/wiki/Substance_dependence
On top of that addiction is no excuse to harm others by stealing or other activity. It might feel absolutely horrible not to have the drug, but it is not necessary in order to live.
Someone who is so consumed by their addiction that they have no self control left, and they steal, is someone who is not employable.
This doesn't mean they should be ignored - it's two different things. People should certainly help them, but at the same time they do not make good employees.
Drug use includes a risk of addiction, not a guarantee. Just like a lot of activities, there is a choice to be made considering the risks involved. For some people, the level of risk is acceptable. Unfortunately, brain chemistry is very complex and users rarely take the time to understand what they are doing to themselves. The result is often an unexpected rollercoaster of self-destruction.
they do not make good employees.
On that point I agree. I'd be willing to look the other way at drug-related charges for a fully recovered junkie, but someone who is in the middle of the recovery process (or possibly hasn't started) would be a no-go.
I guess what I'm trying to say is that we need to stop demonizing drug users. Addiction isn't an excuse for criminal behavior, but it shouldn't be a crime or carry so much social stigma.
I would consider it like bread.
> a physical dependency
Was it their fault in the first place? i.e. did they start using it for a good reason and are now dependent? Or did they start using it because they like how it feels?
> What if it's life critical
Like bread.
You are being a bit too simplistic - the specific details don't matter, what matters is the person's state of mind. Is he stealing because he does not care about the other person, and only about his own enjoyment? Or is he stealing because he has truly no other choice and he feels bad about it?
It's impossible to really know someone else's mind, all you can do is judge based on behavior.
They are totally different!
Someone stealing for bread, i.e. to survive, will never consider crime if they don't absolutely have to. So they may have committed a crime, but they are not a criminal.
But someone stealing for drugs demonstrate a level of selfishness that does make them a criminal, i.e. someone who does not care about other people. This is something will not change even if they have enough money to buy their drugs. That selfishness does not go away.