I know a lot of people in Florida who go on cruises frequently. Think of people who are Double Income No Kids, people who are still working, but their kids are graduated from college, retired people who sold their homes, live in a small apartment complex or condo in Fort Lauderdale, they have significant amount of disposable income.
And the more cruises you go on, the more deals you get. So it makes it relatively inexpensive to upgrade to a room with a balcony.
I have been on a few cruises, and just didn't like the whole atmosphere. Or the amount of people. Some people love cruises. Others, like me, not so much.