Well, I just came back from the Caribbean two weeks ago, and 'lots' of passengers were carrying boxes (with handles) that were obviously two-packs of rum.
I think they wouldn't want to de-box, and have two loose bottles to try to cram in their luggage.
Now that I think about it, I'm wondering 'how' and 'if' they carried those boxes of rum onto the plane. I don't see how they could have.
I don't remember bottles of alcohol being addressed in the Transportation Security Administration guidelines. I mean, they don't exactly fit into the "3-ounce bottle of liquid" carry-on rule.