The author conflates small outward-facing practices with small inward-facing practices. I don't think they are the same.

Arguing about small outward-facing stuff is just bikeshedding. In the case of the "n/a" versus "ø" debate, you should settle it with an A/B test, some paper mockups, or even just by manager fiat. If a manager's job is not to keep the developers away from unproductive ratholes like this, then what is it?

Arguing about small inward-facing stuff, like house coding style, is about control of one's own environment, and having a pleasant workplace. So it may well be a matter of human dignity and respect to let them spend "useless" time on it.