People
did get angry at what he
did say so there's no need to concoct thoughts in his head.
If the reporting is accurate, his words were twisted. He said "I strongly disagree we live in a white supremacist culture" (meaning American culture) which another employee changes to "white supremacy doesn’t exist."
Based on what was reported, I don't know why Singer was suspended. I do understand why he resigned, given the reaction of many employees. He's not an avowed white supremacist.
Singer is very wrong, he needs more education, but it seems like many of the employees can't handle the idea of working at a place where someone so wrong works. At a large workplace, there was another worker who I saw coming in to work had a large sign on his bag making clear he was a 9/11 Truther. I saw he also sat at lunchtime with his bag prominently displayed (not at the workplace, in public). It made me really angry but I'd never do anything to threaten his employment or avoid all contact.