This is such a complicated question because it gets into the origins of religion and belief systems in general, but also power and class struggles, economics, social psychology and propaganda, and more.
Lots of people haven’t been properly educated Lots of people have been indoctrinated Lots of people have a reason to exploit the beliefs of others Lots of people value comfort and community above scientific accuracy or consistency
Lol “moral obligation”. You don’t do it because you’re obligated. You do it because it’s nice for the worker, and for the other customers who don’t want to navigate around your abandoned cart