Quoting my own post, let me give an example of what I meant when I wrote "unfriendliest ship". On the first night when we went to dinner, we were asked would we like a table for 2 or a larger table. Since we like meeting people, we opted for the larger table. We were seated, and then waited, and waited, and waited, until we finally went back to the front and said a table for 2 as it was obvious that no one else wanted to meet strangers. We never again asked for a larger table.
And in general, striking up a conversation with fellow passengers was much more difficult than any of the other cruises we were on. DW thought it was because we were in Europe, but almost half our cruises have been in Europe, and it was never like this.
Another example, at our meet and greet, almost no one who had been posting on the roll call showed up. Even the person who set up the meet and greet with NCL did not show up!