I wouldn't neg someone for it, but someone holding absurdly irrational beliefs (like one race being inferior to another) for me would seem less trustworthy to do business with. It doesn't matter if they know someone's race/ethnicity/gender etc, their absurd beliefs are not based on facts or knowledge anyway.
Too often we see ethnic/racist/sexist/etc slurs used as "arguments" in disputes (for example see the recent drama with Koil) to think that prejudice here doesn't affect business.
In my case, it's not that I wouldn't do business with someone who believes, for example, that people of a certain ethical background are inferior, it's just that I don't have any kind of relationship with those people, let alone do business with them.
But I don't think you can apply the argument universally. Someone can have completely irrational beliefs and be very reliable for business. From my radical atheist point of view, belief in god would be something similar, or that praying is going to have any influence in the real world, and yet there are many believing people that pray you can do business with.