His audience are CS students: As a professor, I worry that the upcoming generation of programmers is missing out on the Unix experience, and with it, the power it grants.
Your answer is too simple for them.
Your answer is too simple for them.
It should be strongly mentioned that "unix" best describes a class of operating systems including "proper" unix systems like OSX and the "unix-like" systems like linux.
It's also important to divorce the students from that layman perspective of "operating systems are all that graphical shit I see on my screen". In fact, I think that might be the most important part.