Like prayer, evangelism is a touchy subject for faculty, probably more so. In the academy, Christianity is viewed as out of date, intolerant, and pushy. This is primarily because of the exclusive truth claims it makes. Evangelism as traditionally understood and performed exacerbates nearly all of the issues our colleagues have with our faith.
How dare we say that Jesus is the only way! How dare we even consider telling others that they should convert from their own worldview! It is a beautiful expression of their culture and individuality. How dare we declare that certain activities are unacceptable and even sinful. Morality is outdated. Ethics are the new standards and if my personal choices do not directly harm you, then what right do you have to tell me they are wrong?