Being a better speaker doesn't necessarily mean your ideas are going to get worse.
Being a really good speaker is not merely orthogonal to having good ideas, but in
many ways pushes you in the opposite direction.
These two statements seems to be in direct contradiction of each other.
I must have gotten the wrong message from that essay. It seemed to me that from about the third paragraph onwards you were itemizing the bad things about good speakers.
When we need to expand our ideas to the masses, however, the focus becomes less on what the idea is, and more on how it's delivered. Preying on emotion, sequential logic, and subliminal notes, sometimes even the worst of ideas are promoted as good ideas.
In accordance with the last point of your essay, I'm not sure either, that speaking is used more for good. But if that's the case, now that we have so many people with good ideas, perhaps it's time to focus on delivering good ideas, and making the world better that way. (hmm... I just had an idea)
An idea is a signal. It's difficult to send complex signals over long distances while maintaining fidelity. We have to focus on the delivery. So we engage our audience emotionally to get them to listen and repeat messages we want people to understand. Subtle abstract notions are even difficult to deliver at close range. How difficult would it be to deliver one to a crowd without adding more energy (emotion) or simplifying it.
We shouldn't always blame people for not understanding. Sometimes there are good reasons for doing things the way we do them.
> It's just alarming to me how little being a better
> speaker depends on making your ideas better.
However I do think that spending some time thinking about how to present your ideas in oral form can indeed help to improve them.