The further up the academic ladder you go, the more theory work you encounter. I'm not a theory person. It's always irritated me when people name drop a theorist in non-academic discussions (particularly in the pub). Maybe it's my own insecurity, as it's usually a name of someone I've heard of but never actually read. Somehow, I managed to get through undergrad without having to read much theory--but now I feel a bit like an English major who's never read Shakespeare. I read a bit of Habermas and Derrida, but as a European Studies major, the reading was about the Old Europe/New Europe paradigm--current events in 2007/8, not exactly the "theory" pieces that made them famous.
Fun fact: When you google image search their names, you get the same image--an old white man posing in front of a bookcase...
Theory doesn't exactly come into my research project, and I'm not sure what to do about that. Phil Taylor used to get irritated by scholars who talked about public diplomacy theory. He said "Public diplomacy is a practice, not a theory." He was right--there is no theory of PD. There are, however, some scholars who think the field needs theory. I recently re-read Eytan Gilboa's "Searching for a theory of public diplomacy" (Annals, 2008, 616). He shoots down every attempt that scholars have made to relate theories and models to public diplomacy. After criticising the field for about 20 pages, he notes that "some progress can be found", and points to his own models among a handful of examples. He closes with the call-to-action statement that the field needs theory design and implementation--but I'm left wondering where to start, after seeing him disparage nearly every approach out there!
Personally, I don't think anyone needs to formulate a single theory for PD. Its interdisciplinary nature means that "PD theory" can be borrowed from existing theories in these other disciplines--international relations theories, communications theories, etc. Although that means I'll have to read some theory literature in all of these fields now...