For decades, they've lived by the gillnet. It's only natural they should die by the same....
Today, commercial fishing (not to be confused with processing and distribution, which are highly profitable) is a marginally profitable enterprise. I'm sure most commercials would gladly pursue any opportunity to harvest more of the target species were the gear adaptations associated with changing their methods not such a huge disincentive. It's probably legitimate to argue, considering the profit potential against the cost of switching gear, that switching gear is effectively cost prohibitive. I think this explains, almost entirely, why the commercials refuse to entertain the discussion. I sympathize with that, but no amount of sympathy will change the fact that gillnets are fast becoming a non-sustainable harvest method. If their tradition is to carry forward past the next few years, they will need to adapt.
One would think there would be a price point at which consumers would stop buying commercial fish, but I think we're finding that not to be the case. Consider, for example, the price per pound a sushi grade bluefin tuna commands, or recall the price per pound on spring Chinook in a low return year. No matter how outrageous the cost, people come out of the woodwork to pay it every time. Indeed, as a species becomes more scarce, the fugged-up nature of human culture makes that species a delicacy and a symbol of high social status.
Certainly, people won't be willing to pay those prices for Coho, but what's the breaking point there? I'm sure we haven't reached it. I guess my point is that if food fish are becoming scarce, and, as a result, commercially harvesting them is carrying an increasing cost/fish, the market price should reflect those circumstances. Don't want to pay sushi prices for a salmon fillet? Go sport fishing and catch your own (understanding that it will still probably cost you more per pound, but at least you'll have fun in the process).