According to Peter Elbow:
People who care about good language tend to assume that casual spoken language is full of chaos and error. I shared this belief till I did some substantial research into the linguistics of speech. There’s a surprising reason why we — academics and well-educated folk — should hold this belief: we are the greatest culprits. It turns out that our speech is the most incoherent. …
[W]e drift into sentence interruptus: a phrase is left dangling while we silently muse — and we never return to finish it. When we academics were in graduate school, we were trained to write badly (no one put it this way of course) because every time we wrote X, our teacher always commented, “But have you considered Y? Don’t you see that Y completely contradicts what you write here.” “Have you considered” is the favorite knee-jerk response of academics to any idea. As a result, we learn as students to clog up our writing with added clauses and phrases to keep them from being attacked.
The Dish 