If the creel survey is the only place they are getting their data from then we're in trouble. To just assume that once a hatchery steelhead is caught and released its automatically going to spawn with wild fish is naive in my opinion. Fish can bite more than once. How reliable is the data from the creel survey anyway.
How else, exactly, do you propose we get catch data. Catch cards often don't get filled out and mailed in. Would you like them to install high definition cameras that can zoom in enough to tell if the fish you just released is hatchery vs wild? Let's get real here. 90% of the people aren't going to lie to a creel surveyor, and even if they (creel) only talk/ witness a small subset of anglers each day, trends like the release of 50% or more of hatchery are still relevant.
The visual observation is close enough to see any present adipose fins on the fish in Centennial Channel. In this location they have never observed a clipped Steelhead (hatchery Steelhead).
I think the point you're missing here is that two hatchery fish could spawn near Borden creek this year. They spread their genetics to their offspring (and there are a number of studies that show genetic changes from just 1 hatchery rearing relating to higher metabolism, lower predator avoidance, etc). Those offspring with altered genetics now appear "wild" and could easily pair up with wild fish down the road. Up until the last few years the genetic influence of hatcheries was poorly understood. With the new research coming out, biologists are taking it seriously and want all the hatchery fish removed.
To say it's not being utilized to me is not accurate. 300 to 400 anglers were out on boxing day for 6 hatchery fish. The Vedder is probably the most fished river in the province when it comes to winter steelhead.
1 day of the year, on the most prestigious derby day, is not an indication of utilization. Sure, anglers might kill a majority of their hatchery fish in December, but come January when multi fish days are achieved often in a number of cases, guys let hatchery fish go all the time. People want to keep fishing, so they let them go.
Lastly, in regards to the no retention of hatchery in the Seymour and Capilano... those fish lost most of/all of their habitat and were/are at extreme risk of extirpation. In those cases, mixed genetics are better than none at all.