Maybe so, but if they won't let me troll for fish off the stern, I'd rather fly.
Of course, I usually travel in a 737, which is a flying Greyhound bus.
A quick trip to Norweigian or Princess cruise line website will give you an idea of the level of entertainment experience you can expect onboard ship.
As far as fishing goes, booking a fishing excursion while in port is usually an option.