I didn't address your previous point about mixing up two things, fixing a bug versus reversing cash flows, so I let me create a plausible hypothetical case of a "buggy" cash flow and how the consensus agreements we come to as users of cryptocurrency prevent them.

Imagine than one of the primary developers of a cryptocurrency slips in a line of code that enables him to grab as much of the coin as he wants (and then proceeds to use this function whenever he needs a new toy). What will happen? Practically speaking, one of two things will probably happen: 1) almost everyone will exit the coin and devalue it down to near zero, or 2) someone else will come along with a new client that removes this line of code and negates the impact of the transfers. I think you're essentially proposing a 3rd option: he should be able to keep any coin he transfers before he's caught. A forking of the coin is also a possibility in such cases, and this will generally be an unfavorable outcome for the group as a whole, especially if the split is fairly even.

Now, I'm not interested in arguing which of these stances is the most moral, that's a big topic and I don't have the time. But I strongly suspect that based on prevalent moral standards, most people are going to choose 2), assuming the coin is otherwise stable and they derive value from its usage. Anyways, whichever choice is made, it's a choice made by each individual involved and this coin only holds value because of these people. The nice thing about crypto is it is a voluntary association, and you can leave if you disagree with the group.