Respuesta :
It is important to monitor your word choice in a professional environment more than in personal affairs because in a professional setting, your superiors could be watching/listening to the way you act and talk. It would not be appropriate to use slang language in a professional setting.
Hope this helps you. :)
The reason is one needs to establish or confirm her/his writing ability in addition to being able to communicate in writing for the professional setting whereas the only purpose of writing (word choice) for personal use is to communicate adequately.