The latter tend to spend way to much time on card games. The former start saying things like "this event is pretty low EV for me, i think I better study/write that paper/work on that project/etc. instead."

How would one distinguish between the scenario in which they begin to apply Magic-like thinking to their regular life and begin optimizing there, and the scenario in which ordinary diminishing marginal returns to playing Magic causes them to switch to the other activities?