In our world, beer helped to create numbers and mathematics; in Gensokyo, it creates a underwold liberation movement.

Pronak said:

In our world, beer helped to create numbers and mathematics; in Gensokyo, it creates a underwold liberation movement.

Beer freed them from having to ration their sake - they have enough wheat to get everyone beer.

Good enough reason for me to declare her a goddess.

The production of beer is the source of civilization as we know it. Alcohol was the only thing that coldn't be gathered from nature in constant manner so we created fields, houses for the farmers, etc.
Civilization is just a byproduct of our need to get drunk (the fact that alcoholic drinks were safer and have less bacterias and parasites than any water around also helped a lot).