I've been doing this for about 43 or 44 yrs now. I can honestly say that for me, the fun is never gone. If that speaks badly of my character, then I'm ok with that. I have thoroughly enjoyed each and every fish I have caught in my life. I have never willingly walked away from a good day (though I have walked away from numerous small fish, only because I thought I might find numerous big fish). And Pipes, while I understand the intent of your post, I must say the line "needlessly abusing the resource" does not ring true for me.
I think we need to be very careful when questioning the motivation of other fishermen. To many people, catching one fish is abusing the resource. Why do we need to draw lines? While some may be happy with a few fish and a gorgeous day, some may want a different experience. I totally agree that it is not only about the fish. But the fish are the biggest part of it, at least for me. Again, if that speaks poorly of my character, then so be it. I'll continue to enjoy each and every one of them. No matter how many. Hope tomorrow I catch 50. Though I probably won't.