I disagree. The moral thing to do would be to respect the stated wishes of the author of the software, who made clear when they published it that no payments of any kind are expected.
If I gave you a gift and you tried to give me money, I would be offended.
I’m not saying free software publishers wouldn’t accept donations - just that publishing free software is giving a gift to the world, and there is NO moral obligation placed on recipients. That’s the point of free software.
What can I say. That you can not see it speaks volumes about your moral compas.
How is this the bridge you're hiding under?
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...