You (the Royal You) does not want WDFW to make decisions based on known data. That would shut down all the marin mixed stock fisheries and move the fisheries into terminal areas where they could be updated based on in-season data.

WDG tried to develop ISU's for steelhead in the 70s and 80s and decided that they couldn't get accurate estimates. So they went with fixed rate fisheries. I won't argue that I think they were wrong, but it seemed to work.

Now, I suspect that they lack the staff to put onto that task (salmon are much, much, more important than trout) and I also suspect that the actual catch data is not available in real time. You would need net catch (daily) and sport catch (at least weekly) and it is now too expensive to get that.