You're both right and talking passed each other. Writing and speaking both have their flourishes. Writing has constructs and techniques that are not strictly necessary just as oration does. There are also factors besides the content that affect the results of both mediums: writing something in my notebook does not have the same effect as posting it to my blog. So, as far as the tools available, writing and speaking are on the same level for recording and sharing ideas.
However, people are more susceptible to spoken word. There is a reason that poetry is read aloud. This can be used for good or evil but it does encourage people to spend more time preparing for the "flourishes" of speaking than the content.
I don't think anyone in this thread fundamentally disagrees with those statements :)