People can and do demand that - no sure why that is so difficult to understand. And there could be consequences for legal but nasty behavior and those consequences would also not violate any laws. Societies are more than just narrow legalistic machines and checking completely out of broader society is tough/comes with consequences.

This is a complete misunderstanding of what the purpose of a law is and how society works.

Everyone always makes demands that go far above the law. Your legal demand to those around you is "don't murder me, vandalize my things and steal the remains". Your full demand also involves amongst others respectful treatment and consideration, and you don't socialize with those you who treat your poorly even though such treatment was perfectly legal.

The law sets the bar for criminal liability. Society as a whole and its individuals freely set the bar for cooperation. A unionized work force is a social group that has formalized in advance the bar to cooperate with them.