This is a direct consequence of middle management. It works like this: marketing boss and accounting boss have to have everyone in at 9:00 for specific reasons

This is a direct consequence of middle management. It works like this: marketing boss and accounting boss have to have everyone in at 9:00 for specific reasons (customers, time-specific responsibilities). Programming boss doesn't need his people in at 9 for any good reason, but his peers all need their subordinates in at that time, and he gets scared for his image among his peer group. If his people are more disheveled and work at weird times, he might look like he doesn't "have them under control". This is also why you get in more trouble for being 20 minutes late than for "throwing a sickie". The first is taken to reflect upon your boss, while the second isn't, even though it's a much bigger hit to productivity.