I was too abstract. I meant that when a message is misunderstood by a large enough chunk of the audience it's the speaker's fault for not knowing their audience

I was too abstract. I meant that when a message is misunderstood by a large enough chunk of the audience it's the speaker's fault for not knowing their audience and their needs. To be clear, you demonstrated the bias I was referring to by casting doubt on the intelligence or job-worthiness of the listeners rather than recognizing what I said about effectiveness being improved if you can get your message to more people.