This is good question and one that is very practical. Communication is one of the most important skills in the work place. There are several reasons for this. Let me name a few of them.
First, the goal of the workplace is to get work done and make money in an effective way. This goal is best accomplished by communication. Higher level managers need to communicate the objectives, mission, and the plans of how to get the job done. These in turn need to let others now. If there is breakdown in communication, there will be serious set backs.
Second, there will also be many obstacles along the way. This is just a part of working in any field. When this happens, communication will be essential as well. Effective troubleshooting requires communication.
Finally, from a social point view, communication is also important. We are all social beings. To create a work environment where there is camaraderie, communication will be necessary as well.
Communication in the workplace is critical. In almost any position in virtually every job, you will need to be able to communicate effectively. This is primarily why so much emphasis is placed on developing writing and speaking skills while you are in school. Add to the mix the ability to communicate through technology and you will have to agree that the ability to interact in the workplace is an essential skill.