Most of my fish is kept for food, there is no way I am releasing a red emperor, they are far too tasty!! In saying that on the old occasion I have had to release them as we had our bag limit. In saying that a lot of by catch is released, spangled emperor, parrot, etc if it is in good condition. I wish fish like cod released better but unfortunately this isn't the case.
I have a lot of family and friends who love fish and I am happy to share it with them, because a lot of the fun is in the catching, although sitting round the table with friends/family enjoying a lovely meal is also very enjoyable! And those people that say fish don't freeze well, then you are packing your fish wrong or freezing the wrong types of fish... Being that I eat fish 3-4 times a week it would be very expensive for me to go to a shop and purchase it, and besides you typically get crap anyway!
In saying all of that if I go snapper fishing, i will release most of the catch unless someone i am out with wants one for the table. They don't eat well compared to other reef species however they are great fun to catch on light gear. And the big breeders are always released if possible, a 2-3kg fish is much better eating than a 5kg+ one.
PS if you don't like eating fish, why go out and harm animals for fun? Thats a bit like spanish bull fighting isn't it?? Plus there is all the other environmental impacts like pollution, etc.... Hence why C&R has been banned in many overseas countries !