I suspect that state requirements for private homes only come into play when building, selling, or perhaps seeking a permit for a home business of some sort. I doubt that anyone really thinks that any authority can use that for a search warrant.
Re:
"Hell, open the window." As previously mentioned, many would worry more about sleeping with a window open while traveling, and it's just not an option with some rooms, including many ship rooms. It's probly not a popular idea in our blizzard belt either, as CO risks are not limited to times of home heating but are more common then. Do homes have heaters in Kuwait? I guess the need would be more common in Georgia, but some will present ideas for not spending $30, then shrug off the anomalies of some dead people.
For any home that does burn fuel for some reason, cooking, heating water, comfort, fireplaces, etc. they are a reasonable addition. Taking one on trips might be a bit much, since they add several ounces to luggage limits - or maybe not.
But then on my dive trips, I've noticed that most compressor owners don't bother with CO monitors either. It's usually ends up about the money needed for an illusion of safety.