I eat most of what I catch but if I am not going to eat it, the fish is going back into the ocean. We really can't afford to over fish our favorite fishing spots.
When I'm crappie fishing, I catch a lot of sand bass and catfish, I let them all go, mainly because I'm after crappie and that is what I want to eat. But I know many that crappie fish all the time, their freezer is full of fish so they catch and release. So they are just fishing for sport, I have no issue with that, but just me personally, I would not do that, just not interested, that is just me though.