I think part of it for me is in hearing the joke, I hear the subject reduced to simplicity, in some cases with ugly stereotypes, so I feel compelled to explain the nuance.

A recent example came up when someone made a 72 virgins joke recently (the promised heavenly reward for a muslim man who lives rightly features seventy-two concubines)

And as a result, I broke into an explanation of Houri (but spared them the complexities of jihad ).