You are simultaneously arguing for 'moral' subjectivity while utilizing the strawman of 'moral obligation'. Who would enforce this 'obliging' if the subject of morality is still up for debate?
You are tying yourself in embarrassing knots over someone spreading their wealth, unsolicited, to people who helped them achieve it? Why? What's the end goal?
Go argue with someone about the morality of environmental impacts of tech... or something...