So this is my first SMT proper game. I'm about 5 hours in and enjoying the hell out of it so far. One thing I'm really curious about though. The system wherein you ask the enemies you are fighting for money...and then they give it to you...and then they let you kill them.

I've played my fair share of JRPGs and I love me some stupid bullshit. But this just seems strange to me. Is there some logic here that I'm missing? Maybe some folklore that I don't have knowledge of?

Your dude's just that damn smooth.

You don't really get enough Macca out of it for it to be worth the tedium. If you're looking for the why, I think it's implied you just annoy the demons so badly that they eventually cave and pay up. Demon negotiation's always been funny and full of dumb quirks; they'll just as soon tear your neck open for a harmless comment as they will sing your praises for it.