That used to confuse me too. I've come to the conclusion that the reason people focus on things that don't ultimately matter is because it's easy. Anyone can see that someone isn't wearing a suit, works odd hours, doesn't file their TPS reports in triplicate, etc...

On the other hand big problems are hard to solve. People frequently bemoan the glut of poorly skilled individuals who claim to have software engineering skills. One would assume that that there could be a similar ratio of crap people in other fields, management, for example.

In short; managers focus on these things to an extreme because they are bad at their job and policing people's wardrobe is the fizz buzz of the management world.