Mass market lines appeal to the masses - who seem to want low prices and glitz above all else. Anyone who experienced cruising before about year 2000 must be hard put to recognize what is now offered. Well prepared meals, well served, itineraries which included ports not overrun by thousands of budget-minded day-trippers, various types of live music in various venues, thoughtful lecture programs - keyed to the itinerary of the cruise.
What is now offered is a totally different product. Yes, cruising is more affordable to more people - but only because much less is offered on cruise ships.
While I earlier found value on lines line Princess, HAL and Celebrity I now only see low fares for cruises which are less worthy of my time - and, regardless of the low prices, not worth the fare required.