Whether we like it or not, ultimately there must be a demand for this sort of quantity of fish, otherwise it would not be financially viable to the big boys.
I don't pretend to know the answer, but if one is wishing to preserve stocks for the good of the species (and the food chain above it) then that is a good thing, if however they wish the stocks to be preserved so that we, the recreational angler have some sport left, that is probably not the right reason.
If the debate is the unfairness of the quota system then i fully agree that there should be a quota system, but it needs to be something more sensible than "dump all your dead catch so you don't exceed your limit".