People use the Q & A time for their soapboxes, and as an opportunity to upbraid the speaker for not mentioning their favorites. “What would you say is the impact of…” or even “I notice that you didn’t mention…” No actual question, hoping to elicit important new information from the expert, occurs.
The speaker’s most acceptable answer is “I was planning on covering that in detail in the afternoon breakout session,” letting the questioner know that yes, I do get it about animal rights, or the need for light rail, or whatever, with the added benefit of complimenting her that she is spot on by elevating that topic to the top shelf.
Folks tend to remember it more when it is a religious topic being “injected” into the conversation, and I have some sympathy. There are times when it is clearly forced, and we all inwardly groan. Yet I also notice that lots of other issues are “injected” without the audience generalising about the speaker’s group. That, I imagine, comes from the presence of an installed narrative and confirmation bias.