Nefario is paying me to develop the software for his bitcoin corporation. I know he will try to make a profit off of it. Meanwhile, I will get paid 120 BTC a week. That's an actual agreement in real life.

Is that exploitation? No. I like the arrangement in question.

This is after all, an amicable agreement between two moral agents. You, the outsider, is just an observer, who have nothing to do with the exchange. Whatever you think is exploitation is completely irrelevant to what I thought is a good deal, or what is moral.