Two notable excerpts from the article follows:
Typing can be too fluent or too fast, and can actually impair the writing process.
The result of slowing down was a richer vocabulary in the one-handed writing. This allows a better expression of complex ideas.
I often found that my review process on chapters that were quickly produced were more tedious and painful. Apparently switching to one-handed typing or imposing another handicap may generate higher quality works.
That or it would make my writing more flowery and eloquent. That may work well for Victorian-era literature but not be necessarily suited for today!