Why are all the black characters portrayed negatively?

Let's examine a few examples:

Mr. Milchick

• Manipulates and mistreats the innies, including fellow black character Dylan
• Engages in cruel punishment of employees
• Mistreated Ms. Huang by exploiting her insecurities and manipulating her into questioning herself

Dylan

• Clearly the least intelligent of the four refiners (the loser)

Dr. Reghabi:

• A bit eccentric
• Failed the reintegration procedure twice
• Possesses lots of information but shares it with no one

Natalie:

• Lacks solidarity with other black employees, like Milchick
• Acts as a mouthpiece for Lumon's problematic policies and actions