No it isn't. In no decent society will people allow the children of drug addicts to starve to death because their parents aren't taking care of them. It is UNREASONABLE for you to expect us to sit around and allow such a thing to happen. We wouldn't allow it to happen to an animal, let alone a human being.
By not taking care of their responsibilities, these drug addicts are forcing these unwelcome choices upon us, because for us to deny our help to their innocent victims would make us something less than human.
So ALL people, including childless ones, should be subject to imprisonment for possessing pot because SOME pot smokers neglect their children?