Actually I would suggest the more addictive a drug is, the more dangerous to society it is when we make it profitable to sell it, by making it illegal and so sending the price sky-high. If something isn't really addictive, when it's banned people swear a bit, and do without. But if you're really addicted to something, obtaining it regardless becomes a priority.

Maybe if they took the profit out of selling drugs, one effect might be that more people used them, or rather, they might use a wider variety of drugs than they do at present, when most people stick to the currently legal ones such as alcohol, nicotine and caffeine. However, even if there was wider drug use, it would be probably be a great less harmful to society than the present situation, since no one would need to steal to obtain them, and no one could make a massive profit by encouraging others to buy them.

I'm sure that when prohibition of alcohol in the States was abandoned the amount of social drinking rose - but I doubt if the amount of problem drinking rose proportionately.