Don't forget that a Voyager or Freedom class ship is not as confined as a 2000 passenger ship. I can tell no difference in passenger density between the Freedom class and the smaller classes (Vision, Radiance, etc.). Actually, I think the passenger space ratio if higher on the larger ships.
I am being serious too.
On the Liberty Of The Seas last month I never found a line longer than 10 people at any food line in the buffet - even at peak times. I've seen longer lines on smaller ships. I always got an elevator within a couple minutes. I always found a deck chair - even by the pool thanks to some good pool attendants enforcing the rules.
I like small ships a lot, but a big ship has more "stuff" to do and sometimes you want that. As long as the ship is properly designed, the passenger loading just isn't an issue.