I have a friend who was addicted to both cocaine and alcohol. While he, of course, is convinced that cocaine is one of the worst substances to have ever existed, he is even wearier of alcohol because of: (I'm obviously both paraphrasing AND excluding most countries with a Muslim majority here)
a) Social acceptance. No one is ever going to judge you for quietly sitting in the corner of a bar drinking your beer. Try snorting a line on the same setting and see what happens.
b) Availability. Even in sparsely populated areas, you are never too far away (say, a 10 minute walk) from a bottle of wine/spirit/beer.
c) Practicality (which is what answers your question). You don't need a syringe, spoon, knife, bill, bong or lighter, not even another recipient, to start binging on booze. Once you buy/steal the stuff, you're all set - and drinking something definitely IS more 'natural' (as in, it's a reflex) than injecting or smoking something.