Some may disagree, but I suspect it's not a very effective use of manpower to assign a dozen or so crew members to man every single camera at every single angle 24/7 just in case some drunk decides to go overboard sometime during a cruise. "All right, crew, monitor those cameras and for God's sake, don't blink!"
True enough. Another poster above noted that the thing has 15 decks and over 3,000 passengers. That would be a logistical nightmare to babysit everyone.
Cruise ships are a good way at seeing how the rest of the world does things.
In America, we are used to mall security and theme park security monitoring our every move. Some people figure that if they pay a thousand dollars for a vacation, they're going to have someone watching them with a safety harness but that isn't always the case.
At the same time, why hunt for a man overboard if you aren't going to monitor the cameras live? If you don't respond within minutes, he's a goner anyway.