Lack of collaboration in design
In the early stages of the web, there wasn't as much collaboration between web designs and larger advertising campaigns, customer transactions, social networking, intranets and extranets as there is now. Web pages were mainly static online brochures disconnected from the larger projects.
Many web pages are still disconnected from larger projects. Special design considerations are necessary for use within these larger projects. These design considerations are often overlooked, especially in cases where there is a lack of leadership, understanding or concern for the larger project to facilitate collaboration. This often results in unhealthy competition or compromise between departments, and less than optimal use of web pages.
source: wikipedia