I'm not a theorist, and I don't play one on the internet either. Still, I had a few chuckles reading this article. It certainly presents a case justify the pursuit of theoretical physics.
Certainly, theoretical physics is what makes the rest of our work in physics not simply "stamp collecting", to quote Rutherford. It is also interesting for me to observe that many young, new students who are interested in physics tend to gravitate towards theoretical physics AND particle physics, i.e. the 'sexy' aspect of physics that are getting a lot of media coverage. It is only later on in their pursuit to be a physics major that "reality" hits them and they discover not only the experimental aspect of physics, but also other topics and fields in physics. And we must also not forget the "employment" picture.
Of course, those are not within the scope of the article that I cited. I suppose that if you are already employed as a theoretician, then certainly the general public should be aware of what you do and why it should be supported (I support it). But if you're not, it is going to be a tough nut to crack, especially in this climate of budget cuts.