There are certain jobs that require a set schedule. If you're in customer service or dealing with clients, you need to be available (although in this day and age, a blackberry allows you to be available all the time) during "standard office hours". And of course, shift work requires set hours.
At one point when I was doing a lot of fieldwork in consulting, I worked at a place where management demanded that all personnel work the same "standard" hours. Didn't matter if you were the receptionist or the office manager or the field doobie spending 95% of her time outside.
If I'd worked 12-13 hours a day in the early part of the week and then got back Thursday night or Friday morning, I was expected to put in a full day in the office on Friday. Didn't matter that I was already Ms. Billable and that nobody was going to give me more office work because they knew I'd be out in the field the next week anyway.
If I end up in charge of an office, you can be damn sure that I'll allow people to work whatever hours work for them, as long as the work gets done and the clients know they can reach who they need to.