ABCD: Is it productive to call out racists in the workplace?

In my experience? No.

Why?

If you call them out and not everyone in your office (especially people in power) agree with you and have your back (and get rid of the person), you're the one that's going to be ostracized.

You might feel good and that you did the right thing, but unless you have enough currency in your organization and a fail safe exit strategy (and some parents with money), you're screwed.

My philosophy is to take all out guerilla warfare on the person(s) or the entire organization. Don't let folks know what's going on, but have a plan and be ruthless in your execution.