You give a good argument but catch and release effects certain species more than others.  Salmon in river arguably should never be allowed to target catch and release due to the extreme mortality rates that can occur from simply being hooked and netted.
Catch and Release mortality awareness is constantly pushed especially by conservation groups for a good reason.  Someone selectively harvesting certain fish can kill a whole mess of undesirable fish in the process.  As well an angler can catch certain species, yank them out of the water, yank the hook out, throw them back and expect all of the released fish to survive.
Using Kenai rainbows is a bad example and many of their wounds are mostly likely inflicted by salmon fishers.  Regardless the Kenai is a great example of the success of catch and release rainbow fishing and 30+ inch fish continue to be caught regularly.