I see one major flaw in your post, and that is about the fish spawning three or more times by the time they are that large. While that may be true of hens, I believe it's been found that a majority of male steelhead die after the rigors of spawning, and most do not get the chance to flush back to sea for another go round. That in and of itself would disprove your statement.

Another thing to bear in mind, (and I don't mind fishing behind others either.. I catch a LOT of fish behind everyone else..) is that fish are on the move. There are a lot of fish that just don't get targeted in the "in-between holes traveling water" and see absolutely no pressure until your the one that intercepts them in a hole.

In recent years, I've also personally witnessed a larger majority of the pictures, and fish caught, to be treated much more friendly and take off with little to no reviving. Most of the fish I catch shoot off like a rocket.. Some before I have a chance to actually snap a pic of it laying in the water at my feet. People are learning how to treat these fish when it comes to C&R.. It might be a slow learning curve, but I do believe it's working...