Luckily I didn't last till that part. You can use simple language without being vulgar or coarse. An entertainer can afford it, a startup probably can't.
I think you missed the point, but there's an interesting point here: you are not necessarily your own audience. Clearly coarseness is a bad strategy to reach you, personally, but that doesn't mean it's a bad strategy to reach your target audience. You should speak the language of your target audience – in John Oliver's case, the people who enjoy his (frequently coarse) style of humor – rather than your own. Edward Snowden has largely been trying to explain things in a way that people like himself connect with – and that has actually worked pretty well, viz. nobody on this site would fail the "who is he and what did he do" test – but most people aren't like himself.
That's my point - an entertainer usually has an audience centered around their personality and it's derivatives. As a startup your audience is much more vague, often almost everyone. And when you do have an audience it's probably centered around something different.
I totally disagree that a startup's audience is more vague! If you're attempting to reach everyone then you probably aren't reaching anyone. Or do you mean post-traction "startups" who are trying to grow outwards from a smaller audience they have already won? If so, I suppose I agree with you, but I think the term "startup" is pretty dubious (though still widespread) in those cases.