Academics harbor different fears, a topic, which of itself, would merit a series of blogposts.
As we are often called up to speak in public, whether in front of our classes, at conferences, or at seminars, public speaking is, typically, not one of our fears, although, honestly, I know of several faculty who, literally, are so frightened of speaking in public that they vomit before classes and giving talks. (I would recommend teaching online to these folks.)
When an academic gives a seminar or speaks at a conference and has spent a lot of time not only doing the research that she is to speak on, not to mention all the time it takes to prepare a well-thought out and engaging presentation, she would welcome a good audience. By a "good" audience, I mean an attentive one, and one of a decent size.
John L. Jackson Jr., writing in The Chronicle of Higher Education, has a most vivid rendition of a talk that he gave 10 years ago to which noone showed up except for the speaker (John, that is) and the person that invited him. And there were fliers posted up that he could even see. The article made my heart bleed for him. In the article, he argues whether we have simply too many seminars (and, perhaps, folks are too busy) to attract a good-sized audience.
He does note, however, that student-organized events, including talks and seminars, tend to draw a large audience. Indeed, this is the strategy that we have been using for the past seven years or so, when we organize seminars as part of the activities of the UMass Amherst INFORMS Student Chapter. As this chapter's Faculty Advisor, I have over the years only missed about two out of seventy plus seminars (I even traveled back from Harvard during my sabbatical in 2005-2006 while I was a Fellow at the Radcliffe Institute for Advanced Study to support the students and the speakers).
In an earlier post, I wrote about how to organize a great speaker series and related issues (and, clearly, part of it is to attract a terrific audience, since, otherwise it is insulting to the speaker).
Folks regularly tell me how wonderful our speakers are and that their talks on Fridays are the highlights of both students' and faculty members' weeks!
We've even had TV news crews show up to interview some speakers, but we strategize well and disseminate the talks really well. The students do an outstanding job in hosting and following up with thank yous.
We have now started a "Meet the Executive" series, which is attracting students (grad and undergrads), faculty, and others from throughout campus.
I remember, on a related matter, a New Year's Eve party that my husband and I were invited to back in our Brown University days. It was organized by two physicists and my husband ended up being the only invited guest to show up.