The other day, one of my clients simply wanted to give up on explaining his concept to the typical 50% of people who "simply did not get it".
In life there are many situations where you "give up" on certain people. Students who fail the entrance exam of a university, job applicants that did not make the cut, athletes who miss the qualifying threshold for the Olympics, contestants who did not make it to the next round of American Idol.
When presenting your company, you need to put the blame not on the audience, but on your presentation. Your targeted audience should understand your message. And that audience can differ: a presentation to a general audience, journalists, scientific experts can build on different levels of pre-existing knowledge and background.
Often, as a presenter you suffer from the curse of knowledge, you are so deep into your own story that you cannot possibly imagine how someone who is new to the subject cannot get it. Another reason for the disconnect is different types of reasoning/thinking of people. When people frown in disbelief, it might not be because that they did not understand what you are trying to say, they might have a valid different approach to evaluating your pitch that you have not yet covered in your presentation.
When you leave the room, your chosen audience of high school students or elite academics should understand your message. Whether they agree with it, that is a second challenge, but they understood where you are coming from.