The centre part of any business web template has to be kept for showing off products or services. In the centre if there is a place the products or service with little description the users can easily understand what type of business you are running or what they can get from your site. So it is necessary that the layouts give you scope to utilize the space for attracting your visitors cum customers.
If you understand the principles behind website templates you will immediately see the huge benefits to WordPress template systems. Basically it is designed to hookup automated template ideas to a system via which a client who knows nothing about anything can access your site (behind password protection obviously) and update and manage the website that you leave him.