I think you misunderstand the feature. You don't have to constantly update your status. You can set it once in a while to show what you're up to... if you want to.
And what else is the point of that except to let other people know about your hour-to-hour business? Their gif uses "Shipping [software]" as an example, and even has a "Busy" checkbook they they demonstrate ticking off. When features exist, people use them, and when some people use them, other people are socially pressured into using them to conform to peer expectations. This is the beginning of a bad thing for Github unless MS changes direction. That said, Github arose out of the ashes of Sourceforge completely and utterly failing to deliver frictionless value (and the advent of git), so maybe this will eventually provide an opportunity for an existing (or new?) competitor to rise up and take Github's place in the space of "simple network of git repos".
Usually I do want to know about the hour-to-hour business of the people I am professionally developing software with, and I want them to know about mine. When I send a code review to people elsewhere in the company and it's timely, I want some expectation of whether they're around or I should find another reviewer.
