Rules in the Workplace
Companies need standards; there are basic codes for how work gets accomplished and people treat each other. Rules, however, should be kept to a minimum; instead, you should trust that you have hired employees with high quality judgment.
When defining a rule, you have to consider not just the rule itself, but also:
the message it sends to the employees; and,
the unintended consequences. (There are always unintended consequences.)
For example, I worked at a place that wanted high levels of collaboration and interaction. The workplace was designed specifically in mind, in fact, to maximize encounters between employees.
There we have the intent: collaboration and interaction. Therefore a rule was established: there is no work from home.
What message does this send to the employees: we don't trust you.
The unintended consequence: presenteeism - the practice of coming to work when you are sick. Days when employees feel symptomatic with the cold or flu, rather than working from home, calling in to meetings, collaborating via email and IM, they show up, feeling miserable, being less productive, and of course, infecting the rest of the office.
In the end, did this rule really capture its intent and make the workplace better? Unfortunately there are tons of similar examples, but once management decrees a rule, it's usually too entrenched to recognize and correct a mistake.