Here is what I have found related to this. As long as it's not abused there is no issue. We live in a free market and those with the skills to succeed will go where they are the best fit. Some people strive on being the hero and love the recognition that comes with working long hours. Some people are organized and plan and can accomplish more within a shorter time frame.
The reason why we are paid a salary because we are "Learned professionals". We work independently and are knowledge-base workers. Other positions that fall in this classification is Accountants, doctors, lawyers, registered nurses and teachers. To put this another way, our tasks are complex in nature and require advance knowledge to solve and because of this we can't go to a job book to determine how long it should take to complete the task so a job classification was created to justly compensate us.
What happens when management requires their employees to work overtime in these positions is that no actual increase work is completed. We start socializing more in between the times that we must have "face time" in the office. We begin fluffy up our status reports about what we are working on. The focus becomes more about time in seat than meeting company objectives.
That being said. There is always something that needs to be done, that can be improved. Those of use who can't leave things along tend to put more hours in not thinking about it because we have a since of "It's the right thing to do". However, we need to know when to stop and step away to come back to it again later and live our lives.