I would disagree with you on this one.
Company have to know who there're interviewing or employing. As Github is a public space, it's ok to check what your profile looks like.
I feel the same for Facebook. If your profile is a mess, I don't want to work with you. (or at least, hide it behind a nickname)
I wonder what if I have an empty Facebook profile (created 10 years ago to occupy the name) just because I refuse to feed people like Zuckerberg?
We're a place where coders share, stay up-to-date and grow their careers.
We strive for transparency and don't collect excess data.