For an entreprenuer, writing and persuasion may be the most important aspects of their business.  It all comes back to their communication skills.  To be a great leader you must be able to communicate your thoughts to all the people around you.  As an entrprenuer, this is even more important.  You are constatnly persuading and communicating.  It may be simple as giving your employees instructions or actually asking investors for more money.  The better you share your thoughts, then the easy it will be for them to do what you ask.