This is still currently being edited.
How do we choose a particular set of ethics? In my experience, young Effective Altruists and Rationalists, choose consequentialist ethics based on what is prima facie attractive about them. After all, if I’m already purchasing fuzzies and utilions separately then why not do the most good? This leads to repugnant conclusions which they inflict upon themselves to their detriment.
This can range from the rather benign “Between the death of my family and N people stubbing their toe, there is a finite number of people where the former would be preferable” to the more damaging “Am I killing someone because I chose to buy Starbucks today?