I think his point is that intensive addiction is more likely with cigarettes - the high from smoking tobacco is much less intense than that from many illegal drugs, but the high and the addiction potential are different things. You are quite right that intensive addiction to some drug like heroin can be worse, but part of the problem in the US is that being a heroin addict is almost de facto proof of criminality. While attempts to criminalize addiction itself have failed, if you are a police officer and you know someone is a heroin addict then you won't need to wait very long to bust the person for possession. On the other hand, if you become addicted to heroin in some other countries this will be treated as a medical problem and you may be able to manage your consumption in a clinical context at lower expense, social risk and so on.