pg once explained essays are his exploration of an idea and I would hazard to guess in many cases the conclusions are still born out of the act of writing.
http://www.paulgraham.com/essay.html
tl;dr Essaying is not about the writer's clarity of thought but the process of bringing their thought into clarity.
As for professional public speaking look at it in the context of their motivation and why they are up there: is it to promote an idea, sell more of their books or simply get invited to speak again? If their goals are being met then maybe they are an effective (good) speaker. Did it provide real value to every member of the audience? Only as far as it meets the speaker's goal.
pg once explained essays are his exploration of an idea and I would hazard to guess in many cases the conclusions are still born out of the act of writing. http://www.paulgraham.com/essay.html
tl;dr Essaying is not about the writer's clarity of thought but the process of bringing their thought into clarity.
As for professional public speaking look at it in the context of their motivation and why they are up there: is it to promote an idea, sell more of their books or simply get invited to speak again? If their goals are being met then maybe they are an effective (good) speaker. Did it provide real value to every member of the audience? Only as far as it meets the speaker's goal.