in certain societies, certain forms of commerce are prohibited
if you have children, for example, are you happy i sell drugs to those children or use your son or daughter for prostitution?
once there was a tribe of people called 'Hebrews' and they wrote a certain (fictional) book that also included universal moral laws in it, which they called 'Torah'
these moral laws are an example of what guides moral commerce v immoral commerce
pretty straightforward for moral people
in other words, not everything is fit for "commerce"