There is literally not an opinion you can hold that won't offend a significant portion of attendees. Do you believe in global warming? You might seem to be an environmentalist whacko to the conservatives in the audience. Vocally support second amendment rights on Twitter? Some liberals might think you're a dangerous gun nut. Believe that misandry and reverse racism are real? A good chunk of the crowd will believe you're sexist and racist. Don't believe that they're real? Another group will think you're a hardline SJW weirdo.
I have no idea about the political opinions of most of the people I've seen speak. Maybe they'd be my best friend in real life, or maybe they're despicable. I don't know; I don't care. I'm not endorsing or condoning their personal opinions by listening to and benefitting from their technical experience in the subjects I'm interested in.