If A Word Describes Your Position On A Topic Use It

Why are some scientists reluctant to use descriptive words to present their opinions on some topics? Leonard Susskind is a noted physicist who does an excellent job in this 8-minute video of countering religious dogma. He clearly is an atheist and an agnostic but will not declare himself as such (see beginning at about the 6:30 point in the video).

Why do I think this issue is important? Language is how humans communicate with each other and every word has a meaning. Atheism and Agnosticism are words that can stir up negative emotions and, thus, some influential people who know better fail to use them. Until this changes, it is my opinion that the route to acceptance of science-based thinking will be significantly impeded.