Sailed on 10 day cruises in Feb 2001 & 2002 on HAL's Zaandam. On the 4 sea days both pool areas were packed. Noted lots of chair saving by the mature/affluent passengers on HAL. Every chair on the Lido deck pool area was unavailable by 10:30AM., and chairs were lined up chair ro chair. The aft pool area was a little better, but become wall to wall by 11:00. And both pool areas remained that way until mid afternoon, when, I suppose, the pax went to their staterooms for naps?. We quickly learned that if we wanted a chair by either pool, we had better get out early.
So I just don't think you can draw any meaningful conclusions about the quality of a cruise experience or rate any cruise line based on this aspect of simple human nature. People will be people.