Actually that's completely untrue.  Alcohol had the ability to save lives of people in hypothermic conditions and was used to keep the blood warm for many people in colder regions.  Just like their are some retarded alcohol users there are moronic pot smokers as well.  Regardless of the positives to anything there will always be people who over consume anything.  

Whether that's food, alcohol, marijuana, tobacco(not that crap you get in packs) pain medication, or anything else you put into your system.  Any idiot can kill themselves with something as simple as over consumption.  Hell I'm sure at this point food and obesity kills more people than alcohol, with diabetes, increased cancer risk blah blah blah 

You can't cure the human condition. Humanity is bent on self destruction that in itself is a conditional response.