Is there any reason to not make course details public? While attending a course sometime back, I recall an instructor saying, "I need to warn (other instructor's name)...their course syllabus is available to anyone!"

I do not have access to an LMS for my classroom-based course, so I just post my course details to a regular Web hosting service. On the Web site, students, or anyone else, can easily locate:


the syllabus
exam study guide
homework instructions


I cannot think of any reason why this would be a problem, but recall the comment, so wonder if there might be some issue I have overlooked. Is there any reason why any of this information should not be open to the public?
Basically, I would answer no! There are, however, several issues that may prevent people from publishing material openly. One is if it contains copyrighted material, another is if the material contains hints that can help students gain an unfair advantage. In your list, the only possible issue could be with the third if those in any way could lead to an unfair advantage (not that I can think of how). That said, many publish homework questions, lecture materials etc on web sites that can be found by a search. I have benefited from finding such materials when developing my own courses and I am very grateful for that. Returning to your three points, I think they provide a good basis for students to decide what they can expect from the course and hopefully will attract the right students to it.