What is more costly is allowing that behavior to become tolerated and normal, affect employees' morale, ruin the culture, affect the company's reputation, etc.

What is more costly is allowing that behavior to become tolerated and normal, affect employees' morale, ruin the culture, affect the company's reputation, etc. It can also get the company sued. Take a look at EEO laws. You also seem to be forgetting the fact that people don't have to insult or antagonize each other in order to be successful. If anything that is neurotic behavior that is negatively correlated with career success.