I think that we only accept alcohol in society because it is easy to produce and has existed for a long time.
It seems almost certain that if it were a new drug, no rational arguments could support the introduction of alcoholic drinks.
As far as I can see the arguments against it would be:
1. It will lead to unnecessarily dangerous driving resulting in deaths and the destruction of many lives
2. It will fuel aggressive and violent behaviour
3. Some people will become completely dependent on it and it will consume their lives and ultimately may give them a terminal illness
4. It will lead to unwanted pregnancies and other regrettable sexual encounters
The arguments for would go:
1. It will make socially awkward people feel more relaxed
2. It will lead to some interesting new drinks albeit almost all of these will be acquired tastes
I don't see that I've missed anything major here and stacking up the pros and cons leads trivially to the conclusion that alcohol is a bad idea.