I think that we all know that T.V commercials aren't necessarily the way things actually are.
If someone wants to leave their balcony door open thinking they will hear a gentle swishing of the friendly ocean lulling them to sleep, power to 'em-- after getting their cabin full of hot, humid air and spending most of the next day running the a/c full tilt trying to cool it off again, and all the while complaining that the a/c isn't working very well, then let them learn the hard way. If you don't believe the salty humid air enters the cabin, take a bath towel and a chair, leave the balcony door open and place the towel over the back of the chair and sit it near the open door, on the inside. Then next morning, when you shower, use the towel.
And believe it or not, in spite of all the warnings over the inter-com and in printed materials, there are those who still insist in throwing cigarette and cigar butts over the side--it's not likely to blow all the way into your cabin but the possibility is very real that it could happen--remember the Princess ship a few years ago that had a huge fire from a cigar or cigarette butt that was flipped over the side--anyway, suit thy self and learn the hard way !! That's the way a lot of folks have to learn.