This is a stupid topic.
EK run a legal operation. They have a complete department who's only job is to ensure it is legal.
Unfortunately, being legal has nothing to do with being moral or ethical
That the legal operation is hard on the workers, and in some places immoral and unethical is without question, but the operation is legal.
There is no such thing as "morally" or "ethically" legal, it is either ethical, moral or legal. Please do not try to muddy the waters by combining the definitions.
At the end of the day, EK operate within the framework of the law, therefore they are legal.