My impression is also that everything at universities are much more formal than they used to be. (This is based on my experience -- I've been tenured ~10 years at a state university -- and have spoken to older acdaemics about this topic.) I don't know why, and don't think there's a single cause. My guess is that in part universities have come to depend on federal grants and private gifts much more than they used to, for better or for worse: donors don't always give money without attaching strings, and federal grant-making has also become much more formal and bureaucratic. A second possible reason, related to the first, is that federal regulation (both those that deal with education and with research) have become much more complicated, so that a university now has many more employees who are not instructional faculty (tenure track, tenured, or adjunct), and governing from the bottom up is just not practical. Yet a third reason is the constant possibility of litigation -- e.g., related to tenure and all sorts of other things -- so for legal reasons processes like hiring and promotion are highly scripted, whereas they used to be more formal.