1) I quit hunting in 1977. It was cutting into my fishing time. The rest of the guys in my family all still hunt and I hunted for about 15 years. Some still trap. I encourage both. It's given me a closet full of muskrat hides, mink tails, wood duck feathers and deer hide. While I support the RKBA, I have nothing but distain for the beady-eyed, sweaty-lip paranoic turn much of the gun culture has taken since I gave up the shooting sports. So, I'm kinda glad I'm away from it.
2) When I'm around people and discussing the issue, I tell them I practice C&R to demonstrate that I have reached the 4th and final plane of fly fishing wisdom..🙂 But the truth is, I practice C&R because: A) wild trout have enough enemies from bulldozers to developers to kingfishers to Republicans (just kidding..sorta). They don't need me to be their enemy too. However, as T-Bert said; it's a subjective thing. Some trout pops are better able to sustain a certain level of harvest than others. B) Compared to bluegills, crappie and perch; trout (even wild trout) taste like mud to me. C) Carrying, storing, etc. dead fish is a pain in the gear box. I like to fish all day and catch lots of fish. Having to deal with dead fish is an impediment to this. D) Sort of ties in with A: Every wild trout alive and well is a poke in the eye to the people who spend their days (indirectly) trying to eliminate them by building malls and riding four wheelers through the creek, etc. I like that...
So, that's why.