Sure there are bad ways to apply things like dress codes, but if it's a part of getting the team to buy into a greater culture (not as a way to force submission), it's something that has been used a long time.
In the case of the Yankees, in not sure if it is a Steinbrenner- initiated rule or not, but i know for a fact that Steinbrenner was pretty heavily influenced by his military school education, which probably didn't get in the way of instituting or reinforcing the facial hair policy.