At a micro-level, how is taking a plate full of bacon wasteful? It isn't as if the ship is going to reuse the bacon .... everything in the bin is either taken or thrown away. I guess you could argue that if everybody only took whatever amount you deem "correct" they would load less on the ship .. but that is getting nebulous IMO. Seems to me the relevant point is all buffet food is either *taken*or pitched. It is a wash as far
as "waste" is concerned.
At a macro-level, it occurs to me that the very act of first-world people even taking a cruise is wasteful in the sense being argued here. Just like the heaped bacon, the "heaped" dollars spent on a cruise could be used for much better things, at least in the eyes of people who like to judge how others use or "waste" valuable resources.
Just food (so to speak) for thought.