Word (and the rest of the Office suit) suffers from feature creep and legacy cruft. This is a difficult problem because with so many users, removing features is impossible without upsetting a lot of people.
One option would be to split Word into two products: One, called Word, would be a completely new product with a clear focus on the experience of writing and formatting text. This would require ruthlessly cutting out any parts that don't support this goal, including some backwards compatibility.
The other product, called Word Classic, would maintain all the cruft that some people feel they might need. Since the experience would be so much worse, and the new Word would be more prominently displayed in the Office suit, this would help Word users gradually transition to the new product.
