Many haven't been in school or years. Most come to class anxious about taking English. And the majority are first-generation college students. So I feel extra pressure to make sure I don't overwhelm them with logistics, especially on first day.
I doubt that taking attendance, adding and dropping students, and reading the syllabus substantially settles peoples' nerves. Minimally perhaps. But for students excited about the first day of school, too much "teacher talk," regardless how important, might dampen their spirits. The ones already not looking forward to English? Spirits further dampened.