So where does one draw the line between sport fishing and personal use or subsistence fishing?

Catch and release = sport, catch and keep = subsistence?

Much like the words flossing or evolution for an example, it seems that term (sport fishing) has many definitions. In one context it means everyone other than commercial fishermen. The way you use it here it would seem to mean anyone fishing for fun or enjoyment. I happen to find myself enjoying fishing for food sometimes, how do I classify that activity?

Going back to the origin of the pursuit at least, fishing, I seriously doubt the first person to try and catch a fish was thinking anything about fun. Trying to put something on the dinner table was the more than likely the priority.

I'm not playing the devils advocate here at all and am anti-snagging in any fishery that isn't solely for the sake of sustainable harvest, e.g. sockeye in AK.

As sport and/or subsistence fisherman we just need to be careful how we choose our words so we can make sure we are speaking the same language.