Does that mean that the community and activities provided on the boat become the focus?

Yeah, could be. A lot of people love cruises with lots of sea days. One kind is a cruise where a ship is moving from its summer home port to its winter home port, so it might be a longer cruise with fewer ports. They are called repositioning cruises. There's a web site called CruiseCritic.com that has forums for different aspects of cruising, and they have a forum for that.

Wow, 2K+ passengers was a lot in 1975. Stomach viruses are still a problem on ships.