profit is simply that you make more on a trade than you put into it. Could be marginally more or much more, depending on the situation. "Profiting off of others' [work, misery, situation]" can certainly be morally questionable. Still, I would argue that any system that imposes restrictions to limit this - because a few folks get to decide on that morality - is far more problematic. That's not a case you're making but I'm not sure how to limit that (essentially how to prevent ppl from being assholes) without creating a far worse situation.