May be I'm missing something. I thought that part of the original reason cruising dropped off was due to airlines ( i.e., Concord) being able to fly quicker to European destinations -- one of the original destinations for cruisers -- allowing more time once you arrrived. The airlines are what caused the decline in ocean liner travel. It was only when the cruise lines partnered with the airlines and stopped looking at them as competitors that things started to pick up for the cruise lines. Since there are only a limited number of wealthy passengers who could afford to travel on long voyages, shorter trips became more favorable.
"Middle class" passengers make up the bulk of passengers with "Baby Boomers" the largest group. Today it is more common to see grandparents taking their childern and grandchildren on cruises since they have the money and time to travel.
Also, once passengers got a taste of "homeport" cruising with its convience, many of them no longer wanted to deal with air port hassles, flight delays, lost luggage, etc. when they could get to the ports via car or taxi. Plus, they didn't have to fly in early just to make the ship and add more money to the overall cruise.
Yes, the vast majority of today's passengers have to work to pay for their cruises -- they were not born wealthy like the passengers of the past. Does that mean they shouldn't get good quality service? Why does this seem to be a problem unique to NCL? You don't see the other cruise lines having a problem attracting good help. I would imagine that the cruise industry is no different from other travel industries as far as turnover. As a worker you will go to whoever will pay you the best.
So I am confused by some of your reasons for why passengers are the blame for the problems!!!!!!!