Because blogging software has dramatically changed the face of the internet. Anyone can have a free and easy website by signing up for a blog. As a business owner this means the playing field on the internet has leveled and you can have a website without spending thousands of dollars. Secondly, you can read the blogs by other entreprenuers, read their successes, failures, ideas and learn what other business owners are doing.
The web is constantly changing and is being used by more people and businesses because they can understand how to publish a website. The availability of WordPress to not only host your blog, but to be the software that runs your entire business website has put website development in the hands of the users.