The words "We don't do Jewish" in writing probably sound far worse than in real life... They could definitely be taken out of context. I don't think people should make judgement calls unless they actually witnessed the event.
Example, someone walks up to the CD and asks,
Guest: "I see you have religious observances onboard, do you do both Christian and Jewish?"
CD: "We only do the Christian service, I'm sorry."
Guest: "I beg your pardon, I couldn't quite hear if you do a Jewish service?"
CD: "We don't do Jewish."