I know that there is always going to be some mortality, even in a catch-and-release fishery, but that doesn't prevent catch-and-release fisheries from existing.
I also know from being an angler on the west coast that as soon as you catch your quota or your limit on a particular species, you generally move on, especially if you're chartering somebody to take you fishing. When you catch your one coho, you move on to the next fish. Allowing people to actually keep the first marked chinook salmon that they catch means they will move on to other species. I don't see how that would be more damaging than having a catch-and-release fishery that encourages the catch and release of chinook salmon all day long.
With all due respect, I just don't know if the department really understands the mind of a recreational fisherman.