The taste is the value. Mechanically it makes cigarettes easier to inhale.

Obviously sugar provides some calories, but no one is getting fat from the sugar in cigarettes. The caloric value is negligible.

You absolutely wouldn't make the case that sugar is being added to foods in order to add additional calories, or that salt is being added to foods in order to preserve them. The fact that you can come up with a spurious purpose for an additive doesn't make pointing out the additive's primary purpose nonsensical.

The purpose of adding to an alcoholic beverage isn’t to increase caloric content, it is solely to make it more palatable. Restaurants don’t salt their steaks to preserve them, they do it to improve the flavor.