People could think aboutthis for a very long time now and I havent seen any real arguement against it. I think the best we can do is look at other countries that legalized it and then see how it turned out and what exactly they did. We have the USA, Canada, Netherlands etc.
The only thing I think has ben done wrong, is they way you can advertise etc in the USA. In should be similar to how it is in in germany with cigarettes. No advertisement, no huge campaigns etc.. Just stores that can sell buds and some other products, without any advertisement in TV etc, otherwise you will end up with bigger problems. People should smoke weed if they want to, not because they have been manipulated by media/adverts.