Writing code doesn't mix well with oration
I'm not sure I always agree with this.  David Beazley's 2015 PyCon talk on concurrency (<a href="https://www.youtube.com/watch?v=MCs5OvhV9S4" rel="nofollow">https://www.youtube.com/watch?v=MCs5OvhV9S4</a>) was one of my favorite talks of the conference, and it was almost all just live coding.<p>Part of what made that talk compelling was that it took a concept that lots of people find complex/intimidating (how the internals of an asynchronous IO library work) and in ~30 minutes created a full working example in front of a live audience.  Writing the code live in front of the audience helps to nail down the central theme of "this stuff isn't actually as scary as it looks".<p>There are certainly talks that would be better of just presenting snippets of code, but I think there's a time and a place for live coding examples as well.