Hmmmm.
I think there is an important set of ideas here, I don't necessarily think pg expresses them well (which might be ironic, given the topic...).
I love to speak. I regularly give talks to my old school, and another school I went to briefly. Last year I was asked to speak at the university department I went to, which was fantastic. I also love to write; fiction and non-fiction. About myself, about ideas, about made up stuff. I started both of these things, really, in about 2006. At that point I was awful at both - particularly writing. If I could overcome the nerves I was good at speaking, but my writing was disjointed and confusing.
The first lesson I learned is; skill comes with practice.
8 years later, I'm still not the best of writers. But I'm not the worst either. That took me (estimating Wikipedia contribution, forums/message boards, lengthy emails, blogs, etc.) a significant part of 2 million words.
God it was fun!
Over that time I learned a second thing; which is that speaking is hugely trivial. And writing requires intense depth.
I used to look at motivational speakers and think "what a lot of bullshit". Which it definitely is. But it is inspiring bullshit. Speech is about arousing emotion and interest; a good speaker tries to excite a listener into thinking about a topic. And leaves them wanting to find out more about it - typically by reading.
Take "Wear Sunscreen"[1]. Any aspiring speaker and writer should read and understand how utterly brilliant that piece of address is. I only wish it was a real address - because that is a writer who damn well understands speaking!
A good writer has a whole lot more tools to her disposal than a good speaker. For a start she has much more of your attention - it's easy to zone out from a speaker, especially if it's a guy giving your commencement address or a class lecture (where you expect some level of droning boredom). Usually reading is a choice - you are digging into something, and you are willing to process more detail. For a speaker the attention span is much shorter - the listener can't pause and run back over the last sentence. They have to consume in real time.
So for me, well, I want to be a brilliant speaker and a brilliant writer. I want to give you a speech that inspires you, and I want to write about things that mean something to you.
pg talks about the good speaker and mentions laughter as a tool. He pitches that as representing a successful talk, but having no depth. I disagree - I'd say that is a bad talk. Laughter is certainly a useful tool in moderation. But in my experience newbie speakers, who have progressed beyond the "um" (sorry pg!) stage into "I want to learn this art", see a laughing audience and think the nut is cracked.
Far from it! You've got them listening for an instant - but your joke isn't likely to be inspiring. These speakers are the true hacks - they try to hang useful things off of many jokes, and largely fail. I'm not a brilliant speaker, yet, but I think I am past this stage. And what you learn is that a joke can grab their attention - and then you have a short time to make use of that interest. Another joke doesn't give them anything... If he walked away from that talk without any useful information - even a springboard for more research - then the speaker failed.
If he transcribed those speeches and his had more content perhaps there is something to consider; could he use the talents of that "good" speaker to hook the interest of the audience and impart a hunger to read his much more impressive writings?
The art of speaking is to use these hooks. A joke is the simplest - but there are many more. Repetition, as exampled by Martin Luther-King, or irony. The list is really endless.
This is why "Wear Sunscream" is brilliant. The whole thing is a joke, sure; but it has loads of useful advice as well. The speech shifts around, using all manner of hooks to keep the audience interested and amused, whilst imparting advice. And best of all it leaves you wanting to know more.
Which is when the writing comes in.
OK. pg says a lot of the same things as I have; but where he comes off as being critical of hooky speech, I think it has a good place :) We should all be better writers and speakers.
Perhaps this is bullshit too, I don't know, it's probably not good writing...
1. http://en.wikipedia.org/wiki/Wear_Sunscreen