While it's good to question the highly dubious criteria to separate legal from non-legal drugs, I think all these studies showing alcohol as the worst drug fail to account for the fact that if used in a responsible way, the harm caused is practically zero.
A person who likes to drink a cup of wine or a beer two or three times a week, and doesn't do so when driving, receives and causes no harm in practice (I know, there are studies about increasing cancer risks due to alcohol, but no more than with meat and other non-drug products). This is not true of cocaine, heroin or even tobacco, where there is no such thing as a harmless dose, and it is controversial in the case of cannabis.