Obviously none of your coworkers made a conscious choice to be intolerant

That's a huge, and demonstrably incorrect, assumption. I have a friend that treats everyone like that, they're super outgoing, throw huge parties, and invite every type of person you can imagine, and they all show up because they're excellent parties. The bigoted racists gather in their own group (they easily find each other by their stupid shirts) make off color jokes, loudly, except the really bad ones, which they quietly say to each other and snicker like teenagers. I tend to blend in to the background and overhear a lot of what they say to each other. They chose to hate, they view certain humans as lesser beings, and repeatedly act in ways to explicitly prove they're not part of any group outside their own, on purpose. They want, and deserve to be excluded until they're willing to change.