Because nobody thinks drinking is the same as smoking. Asking why some rules are the way they are is a fantastic idea, but consider asking more interesting ques

Because nobody thinks drinking is the same as smoking. Asking why some rules are the way they are is a fantastic idea, but consider asking more interesting questions than "Why is X not like Y". Especially when the answer is just that they are different. Smoking bans is not about "doing something" or "doing dumb things", and if you abstract them up to that level in order to compare them you'll lose all fidelity in your question.