seines vs gillnets on keeping bycatch

What is the deal with gillnets only having a "special request" to release non-target species...some of which are of conservation concern on the north coast? While seines are directed or ordered to release these same non-target species. Why the disparity for gear types? Obviously, we know one gear type will kill most of the fish it encounters, so there is a possibly a waste factor in allowing GN's to keep all these fish.
But, if the conservation or other concern is strong enough to warrant one gear type to release a certain non-target species why does a different gear type get away with only being requested to release these fish?
If you look at chinook in 2008 for example, the gillnet quota for its directed 2 day chinook fishery was 4000 fish ( or the disgusting term 'pieces' in the industry). Yet, in the other 12 gillnet openings for sockeye they kept another 1200 chinook....while releasing only 673. That's a 30% increase over their quota. And releasing 673 out of 1873 means only 35% of the chinook caught were voluntarily released.
This is most likely because of $$$$. Those 1200 extra chinook are worth about $84,000 ( 1200 times 20lbs average weight @ $3.50/lb)
It seems a flawed fisheries management measure to only 'request' fishers release non-target species of concern, especially as fishers have proven which route they'll take given the choice.
And what happened to the premise that chinook (and coho) are primarily sport fish?? Would'nt those 1200 extra chinook be very valuable to the Terrace sportfishery?
And did chum salmon just magically rebound from historic lows over the winter? How are chum salmon, a species of conservation concern with no directed fisheries allowed, suddenly rebound enough to allow their retention as a bycatch extra???
All this begs the question: does DFO manage the fishery or does industry?? Does the Ministry of Environment 'request' anglers use single barbless hooks or 'request' angling guides to keep under their rod day quotas? Of course not, it is ludicrous to 'request' any commercial industry to comply with 'requests' when money is involved.

2009 IFMP Commercial Fishing section
7.6. North Coast Non-Retention Species
There will be non-retention of steelhead in all commercial fisheries.
7.6.1. Seine Fisheries
Areas 3 through 6: non-retention of coho, chum and chinook; chum retention may be allowed in certain areas and certain times, depending on stock strength. Coho may be opened based on in-season information of returning runs.

7.6.2. Gill Net Fisheries
Area 3: Non-retention of coho. A special request is made to release all live chum and chinook to the water with the least possible harm. Chum non-retention may be implemented in-season. Coho may be
opened based on in-season assessment of returning runs.
Areas 4 and 5: non-retention of coho and chum. A special request is made to release all live chinook (except during directed chinook fisheries) to the water with the least possible harm. Coho may be opened based on in-season assessment of returning runs