I agree with gradioc, that was just racism pure and simple. What is so strange about that is that Koppel tried to save Campanis from himself, but he didn't want to be saved.
I hate the word "racism" because, to me at least, it stirs up images of Bull Connor and George Wallace. These people didn't just look down on blacks. They hated them and would go to outrageous lengths to keep them from sitting at the front of the bus.
Campanis IMO was prejudiced, a less-loaded but accurate term. He pre-judged the capabilities of a potential job applicant based on racial characteristics.
That said, it was immensely stupid and he deserved to be fired.