I don't because I have a different version, so it's hard to follow, but also, I don't see the need. I'm listening, so why do I need to read it too?
It also seems a bit rude (it's obviously not generally considered to be!) not to be looking at the person speaking.
I'm torn between thinking there must be some great spiritual advantage I'm missing and that they're all showing off about how well they know their way around the Bible and how quickly they can find the right page 