What is it about speaking at events that you don't like?

I'm speaking at All Things Open tomorrow (register now for free). I'm talking about how New Relic went open source.

I like speaking at events and conferences, especially if I know the topic well. I think it's exciting and sometimes fun. I know that most people don't share my perspective on speaking at events.

So I want to know...

• What is it about speaking at events that you don't like? What deters you? What stops you from submitting a CFP?
• Or, if you have never even considered it, why haven't you?