At an early age is very harmful to drink, because the body has not yet fully formed. And in adulthood, alcohol does not have a very good effect on well-being. Although it depends on every organism, all people are different.
I don't encourage the consumption of alcohol by minors. But at the same time, it is ridiculous to move against the alcohol intake by the grownups. There are substances which are even more harmful than alcohol, such as sugar and common salt.
You're right, most of our concept of what is harmful to health is manipulated by the government and large corporations, keeping the population ill informed, in order to not hamper the sale of certain products and legal drugs.