What? Zuckerberg never seemed "counter-cultural".
Also, and maybe I'm crazy, but Facebook was never cool -- it was always "just" useful. It was a way to learn about people in college and get back to them after you met them at a party. Facebook was a social utility.
It was also better than MySpace, and had more users on it than Friendster. Does that make it cool? Nah, it just makes it better.
I think that the idea that it may have at some point become cool is among... high school kids who couldn't get in, because it was only open to colleges. Later, it became cool to moms and dads because "it's that internet thing and I can see pictures of people I know, cool!".
For everyone else, who were familiar with email and Flickr and hell, even blogs, all that is just noise.
Facebook was never cool -- and if it was, it was cool among the uncool.