Catch and release is a dangerous thing. It makes us forget the point of fishing. Fishing is a blood sport, and we are predators. To believe any different is wrong. This doesn't mean that I keep every fish I catch, but I could keep a limit every time I fished and not feel bad about it; in fact, it might be pleasant. I would however get complaints from home because my wife would get tired of fish. The story you recount of the "snooty" guide is foolish, but it is also foolish to act like there are some species too good to keep. The reason we enjoy fishing is the same reason cats love killing. We are predators.
There is plenty of science to support some killing and some catch and release, but we don't need to rationalize something so visceral. Eating is what we do as apex predators. Now don't get me wrong, I don't care if some of you have evolved beyond your predatory nature; I have not